P1797/1799 Codes
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
How can I tell if I have the correct TCM and selector lever modules??
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
On the cats incomplete monitor:
- Is your temperature gauge working fine? (if the engine control unit does not think the engine is getting up to temperature, then that would be an issue - the monitor would not complete)
- Definitely no P0420 or P0430 code - the monitor will not complete if either of these is present or pending
- I obviously assume OK on these, but just reviewing....
To the best of my knowledge the temp gauge is working, starts off cold and moves up to the middle area after a while. There are no P0420 or P0430 codes on the OBD2 scanner.
How the oxygen sensors evaluate the cats depends on the type of sensor. My understanding (happy to be corrected) for the X100, the upstream sensor is wideband, and the downstream is narrowband (some other cars use narrowband for both upstream and downstream). You can't measure voltage on the wideband, since it is current based, and the only useful measurements come via the ECU, for which you really need to use the Jaguar IDS tool or similar. On the narrowband downstream sensor you can measure the voltage, but in isolation I don't think this will tell you much. I would guess (!) that the ECU checks on the cats by doing a 'oxygen storage' capability test during a period of steady state cruising of the engine. The ECU makes the mixture temporarily rich which removes all the oxygen, then makes the mixture lean which adds oxygen back in, and evaluates how much oxygen the cats 'store' by measuring how long it takes for the downstream sensor to detect the rich to lean transition - the longer it takes the better the cat is working. It only takes a couple of seconds. I don't think there is anyway for you to know when this is happening or how to monitor it.
- any leaks in the exhaust system upstream of the cats will screw up this test by letting in oxygen (but would likely trigger a P0420 or P0430 code).
I'm going to have to check my OBD2 scanner to see if it gives me the info on the O2 sensors. I'll do that next week when I check the fuel trims.
The test conditions for P0420/P0430 are worth reviewing - I would include this in your next drive cycle.
- Engine up to temperature
- intake air temperature > 18 F and Surface elevation < 8,000 ft (not normally an issue...)
- Varied driving for 3 minutes;
then, constant steady throttle 50 – 60 km/h (30 – 38 mph), 1100 – 1475 rpm > 25 seconds
I'll also have to check my scanner to see if it gives me the intake air temp in the live data.
The fact that there are no P0420/P0430 codes makes it hard for me to consider the cats as the only suspect here, even though they are a candidate :-(
- Is your temperature gauge working fine? (if the engine control unit does not think the engine is getting up to temperature, then that would be an issue - the monitor would not complete)
- Definitely no P0420 or P0430 code - the monitor will not complete if either of these is present or pending
- I obviously assume OK on these, but just reviewing....
To the best of my knowledge the temp gauge is working, starts off cold and moves up to the middle area after a while. There are no P0420 or P0430 codes on the OBD2 scanner.
How the oxygen sensors evaluate the cats depends on the type of sensor. My understanding (happy to be corrected) for the X100, the upstream sensor is wideband, and the downstream is narrowband (some other cars use narrowband for both upstream and downstream). You can't measure voltage on the wideband, since it is current based, and the only useful measurements come via the ECU, for which you really need to use the Jaguar IDS tool or similar. On the narrowband downstream sensor you can measure the voltage, but in isolation I don't think this will tell you much. I would guess (!) that the ECU checks on the cats by doing a 'oxygen storage' capability test during a period of steady state cruising of the engine. The ECU makes the mixture temporarily rich which removes all the oxygen, then makes the mixture lean which adds oxygen back in, and evaluates how much oxygen the cats 'store' by measuring how long it takes for the downstream sensor to detect the rich to lean transition - the longer it takes the better the cat is working. It only takes a couple of seconds. I don't think there is anyway for you to know when this is happening or how to monitor it.
- any leaks in the exhaust system upstream of the cats will screw up this test by letting in oxygen (but would likely trigger a P0420 or P0430 code).
I'm going to have to check my OBD2 scanner to see if it gives me the info on the O2 sensors. I'll do that next week when I check the fuel trims.
The test conditions for P0420/P0430 are worth reviewing - I would include this in your next drive cycle.
- Engine up to temperature
- intake air temperature > 18 F and Surface elevation < 8,000 ft (not normally an issue...)
- Varied driving for 3 minutes;
then, constant steady throttle 50 – 60 km/h (30 – 38 mph), 1100 – 1475 rpm > 25 seconds
I'll also have to check my scanner to see if it gives me the intake air temp in the live data.
The fact that there are no P0420/P0430 codes makes it hard for me to consider the cats as the only suspect here, even though they are a candidate :-(
Senior Member
Joined: May 2016
Posts: 173
Likes: 129
From: Castle Rock, CO
Here's one other 'long shot' idea, while I think of it, inspired by P1797, which is rare-ish other than on 1997s with ECU capacitor fails - this one's a bit of a stretch, but I thought I'd mention it for entertainment value :-)
- bad alternator, causing intermittent canbus issues at tcm, causing intermittent loss of ABS wheel speed data (because it is sent to ECU via TCM canbus), preventing P0420/P0430 readiness test which requires wheel speed data at a particular time after startup, preventing reset of cat monitor which is dependent on P0420/430 readiness, causing Jaguar driver's head to explode, ....etc.
- per the heroic crbass fault finding saga - https://www.jaguarforums.com/forum/x...ailure-235134/
The positives on this one is that it does correlate with P1797/P1799, and is a cheapish fix - new alternator.
The negatives - unless you are as smart and relentless Dale was you'd never be able to diagnose it as the root cause, so it's a 'Hail Mary' after exhausting other ideas and getting really desperate...
- bad alternator, causing intermittent canbus issues at tcm, causing intermittent loss of ABS wheel speed data (because it is sent to ECU via TCM canbus), preventing P0420/P0430 readiness test which requires wheel speed data at a particular time after startup, preventing reset of cat monitor which is dependent on P0420/430 readiness, causing Jaguar driver's head to explode, ....etc.
- per the heroic crbass fault finding saga - https://www.jaguarforums.com/forum/x...ailure-235134/
The positives on this one is that it does correlate with P1797/P1799, and is a cheapish fix - new alternator.
The negatives - unless you are as smart and relentless Dale was you'd never be able to diagnose it as the root cause, so it's a 'Hail Mary' after exhausting other ideas and getting really desperate...
Senior Member
Joined: Jun 2023
Posts: 666
Likes: 318
From: La Habra
Morning Dibbit,
I agree, it does seems like someone really screwed up this car. What, to me, is so frustrating about "newer" cars is that it is almost impossible to find a definitive answer to these "electronic" issues. It's almost like the manufacturers were given a set of requirements, they fiddled with wires, sensors, computers and monitors until they met the requirements and never tested the system to see if anything could go wrong. It's now up to the consumer to figure it out each time an electronic system malfunctions. For instance, the "monitor" for the catalytic converter. What exactly is it "monitoring"? If it's the information being supplied by the O2 sensors then why isn't there something telling me that I have a bad O2 sensor? There are no other electronic connections in the converter itself. Also, how does whatever is measuring whatever it is measuring know if the car is in California or some state that does not require the strict "smog" emissions? If all it is measuring is if the monitor reset, then what is it that "resets" the monitor???? If the O2 sensors are measuring the amount of junk that the cat is stopping why aren't OBD2 scanners "California specific"??
I agree, it does seems like someone really screwed up this car. What, to me, is so frustrating about "newer" cars is that it is almost impossible to find a definitive answer to these "electronic" issues. It's almost like the manufacturers were given a set of requirements, they fiddled with wires, sensors, computers and monitors until they met the requirements and never tested the system to see if anything could go wrong. It's now up to the consumer to figure it out each time an electronic system malfunctions. For instance, the "monitor" for the catalytic converter. What exactly is it "monitoring"? If it's the information being supplied by the O2 sensors then why isn't there something telling me that I have a bad O2 sensor? There are no other electronic connections in the converter itself. Also, how does whatever is measuring whatever it is measuring know if the car is in California or some state that does not require the strict "smog" emissions? If all it is measuring is if the monitor reset, then what is it that "resets" the monitor???? If the O2 sensors are measuring the amount of junk that the cat is stopping why aren't OBD2 scanners "California specific"??
The cats are not nearly as complicated as they'd like you to think. The upstream O2 sensor figures out the mixture and communicates with the ECU to adjust injector pulse width. Once the exhaust is past that sensor it goes into the "converter" part. All that does is, with the help of a bit of outside air, cause unburnt fuel in the exhaust to continue to burn. That's why the outlet is supposed to be hotter than the inlet. The only way the car knows when the cat is ready and working is by the voltages sent to the ECU from the downstream sensor. If the sensor is bad (meaning sending incorrect voltages, not electronically dead. If it's electronically dead you will get a different error code), or if the cat itself is bad, the rather simplistic system has no way to know if there is a cat there or not, or if it's not yet up to temp. Hence the monitor not setting. There's no use in monitoring the cats until the system knows that they're hot.
Once set, the monitor "monitors" the voltage of the downstream sensor. If things are working it should see a pretty steady voltage. Usually that's around 0.6v but the point is that it needs to be a certain voltage and steady. If the voltage drops or gets erratic you will usually start getting cat efficiency codes, P0420 and such. That's the only way the system has of monitoring whether or not the cat is doing its job.
The car doesn't know, and doesn't care if it's a California cat or a 48-state cat. An EPA cat will work just fine. The difference is that CARB cats have more precious metal in them than EPA cats, causing more unburnt junk to burn, hence the substantial price difference. You can fit an EPA cat but, if your smog shop does a visual inspection, the car won't pass. Regardless of the tailpipe emissions. This all due to the smog ***** of CA. OBD 2 scanners are not CA specific because there's nothing in the system's programming that is CA specific. Again, because the downstream sensor isn't actually measuring pollutants but, essentially, the temperature of the cat output.
Joined: Dec 2009
Posts: 13,683
Likes: 9,626
From: Wise County,TX
VCATS label for the TCM and Jaguar Parts Catalogue will have the part number for the selector lever illumination module to match the number on the module itself.
The selector module should have a number printed.
The selector module should have a number printed.
Veteran Member
Joined: May 2009
Posts: 12,076
Likes: 3,361
From: home
Just a caution about the temperature gauge? Do NOT rely on that as it's not a gauge but an "indicator". It was designed to stay in the middle of the gauge so as to not "scare" the driver that something is happening because the gauge needle moves around. They would then bring the car in to the dealer for something that was not a problem. The bad thing about this is by the time your gauge moves to the hot side it will be too late.
The temperature gauge is suppose to move around some as the temperature changes but it has been damped. If you want the real coolant temperature use an after market scanner. Which is a good idea anyway to see what your coolant temperatures really are. I like and use Torque Pro.
.
.
.
The temperature gauge is suppose to move around some as the temperature changes but it has been damped. If you want the real coolant temperature use an after market scanner. Which is a good idea anyway to see what your coolant temperatures really are. I like and use Torque Pro.
.
.
.
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
Here's one other 'long shot' idea, while I think of it, inspired by P1797, which is rare-ish other than on 1997s with ECU capacitor fails - this one's a bit of a stretch, but I thought I'd mention it for entertainment value :-)
- bad alternator, causing intermittent canbus issues at tcm, causing intermittent loss of ABS wheel speed data (because it is sent to ECU via TCM canbus), preventing P0420/P0430 readiness test which requires wheel speed data at a particular time after startup, preventing reset of cat monitor which is dependent on P0420/430 readiness, causing Jaguar driver's head to explode, ....etc.
- per the heroic crbass fault finding saga - https://www.jaguarforums.com/forum/x...ailure-235134/
The positives on this one is that it does correlate with P1797/P1799, and is a cheapish fix - new alternator.
The negatives - unless you are as smart and relentless Dale was you'd never be able to diagnose it as the root cause, so it's a 'Hail Mary' after exhausting other ideas and getting really desperate...
- bad alternator, causing intermittent canbus issues at tcm, causing intermittent loss of ABS wheel speed data (because it is sent to ECU via TCM canbus), preventing P0420/P0430 readiness test which requires wheel speed data at a particular time after startup, preventing reset of cat monitor which is dependent on P0420/430 readiness, causing Jaguar driver's head to explode, ....etc.
- per the heroic crbass fault finding saga - https://www.jaguarforums.com/forum/x...ailure-235134/
The positives on this one is that it does correlate with P1797/P1799, and is a cheapish fix - new alternator.
The negatives - unless you are as smart and relentless Dale was you'd never be able to diagnose it as the root cause, so it's a 'Hail Mary' after exhausting other ideas and getting really desperate...
I'll definitely try this since it's simple enough. However, having watched videos on alternator removal I'm hoping it's not bad.
Joe
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
It's not difficult to get definitive answers in newer cars, it's hard to get definitive answers to many things in the Jag. I have two contemporaneous BMWs, and they are light years more sophisticated, electronically, than the Jag, and at less than half of the retail price when new. And they are far easier to maintain than the Jag. There are better diagnostics, AFAIK the programming isn't proprietary, and the manufacturer still has a lot of support for them. The Jag just used sh*tty engineering and proprietary code. The aftermarket support for Jag is shockingly poor and the manufacturer couldn't give a flying sh*t. If it weren't for boards like these, I think all of these Jags would have gone to the junkyard years ago.
The cats are not nearly as complicated as they'd like you to think. The upstream O2 sensor figures out the mixture and communicates with the ECU to adjust injector pulse width. Once the exhaust is past that sensor it goes into the "converter" part. All that does is, with the help of a bit of outside air, cause unburnt fuel in the exhaust to continue to burn. That's why the outlet is supposed to be hotter than the inlet. The only way the car knows when the cat is ready and working is by the voltages sent to the ECU from the downstream sensor. If the sensor is bad (meaning sending incorrect voltages, not electronically dead. If it's electronically dead you will get a different error code), or if the cat itself is bad, the rather simplistic system has no way to know if there is a cat there or not, or if it's not yet up to temp. Hence the monitor not setting. There's no use in monitoring the cats until the system knows that they're hot.
Once set, the monitor "monitors" the voltage of the downstream sensor. If things are working it should see a pretty steady voltage. Usually that's around 0.6v but the point is that it needs to be a certain voltage and steady. If the voltage drops or gets erratic you will usually start getting cat efficiency codes, P0420 and such. That's the only way the system has of monitoring whether or not the cat is doing its job.
The car doesn't know, and doesn't care if it's a California cat or a 48-state cat. An EPA cat will work just fine. The difference is that CARB cats have more precious metal in them than EPA cats, causing more unburnt junk to burn, hence the substantial price difference. You can fit an EPA cat but, if your smog shop does a visual inspection, the car won't pass. Regardless of the tailpipe emissions. This all due to the smog ***** of CA. OBD 2 scanners are not CA specific because there's nothing in the system's programming that is CA specific. Again, because the downstream sensor isn't actually measuring pollutants but, essentially, the temperature of the cat output.
The cats are not nearly as complicated as they'd like you to think. The upstream O2 sensor figures out the mixture and communicates with the ECU to adjust injector pulse width. Once the exhaust is past that sensor it goes into the "converter" part. All that does is, with the help of a bit of outside air, cause unburnt fuel in the exhaust to continue to burn. That's why the outlet is supposed to be hotter than the inlet. The only way the car knows when the cat is ready and working is by the voltages sent to the ECU from the downstream sensor. If the sensor is bad (meaning sending incorrect voltages, not electronically dead. If it's electronically dead you will get a different error code), or if the cat itself is bad, the rather simplistic system has no way to know if there is a cat there or not, or if it's not yet up to temp. Hence the monitor not setting. There's no use in monitoring the cats until the system knows that they're hot.
Once set, the monitor "monitors" the voltage of the downstream sensor. If things are working it should see a pretty steady voltage. Usually that's around 0.6v but the point is that it needs to be a certain voltage and steady. If the voltage drops or gets erratic you will usually start getting cat efficiency codes, P0420 and such. That's the only way the system has of monitoring whether or not the cat is doing its job.
The car doesn't know, and doesn't care if it's a California cat or a 48-state cat. An EPA cat will work just fine. The difference is that CARB cats have more precious metal in them than EPA cats, causing more unburnt junk to burn, hence the substantial price difference. You can fit an EPA cat but, if your smog shop does a visual inspection, the car won't pass. Regardless of the tailpipe emissions. This all due to the smog ***** of CA. OBD 2 scanners are not CA specific because there's nothing in the system's programming that is CA specific. Again, because the downstream sensor isn't actually measuring pollutants but, essentially, the temperature of the cat output.
Well if it turns out I do need a new cat or cats I'm just going to get rid of the car. Number 1, I don't want to spend $2,000 + for a pair of new C.A.R.B. cats and 2/ I don't feel like spending another weekend removing the old ones and installing the new ones and then asking the new Pope to say a mass that it works. I probably could install Non C.A.R.B. cats given that the little station I take it to never looks at anything but the OBD2. I've taken at least 3 cars there over the last few years and all he does is plug in the scanner and print out the info and take my money. But that leaves 2/ installing the new cats. In the words of George H. W. Bush, "Not gonna do it".
Joe
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
If I don't get any TCM/ECM/ABS faults when I run the OBD2 scan I'm just going to leave the selector lever lights alone. I know where the gears are and don't need a light.
Joe
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
Just a caution about the temperature gauge? Do NOT rely on that as it's not a gauge but an "indicator". It was designed to stay in the middle of the gauge so as to not "scare" the driver that something is happening because the gauge needle moves around. They would then bring the car in to the dealer for something that was not a problem. The bad thing about this is by the time your gauge moves to the hot side it will be too late.
The temperature gauge is suppose to move around some as the temperature changes but it has been damped. If you want the real coolant temperature use an after market scanner. Which is a good idea anyway to see what your coolant temperatures really are. I like and use Torque Pro.
.
.
.
The temperature gauge is suppose to move around some as the temperature changes but it has been damped. If you want the real coolant temperature use an after market scanner. Which is a good idea anyway to see what your coolant temperatures really are. I like and use Torque Pro.
.
.
.
I'm just going to use the temp thing to see if there's a big enough difference between the Upstream O2 sensor area and the Downstream O2 sensor area. From what members are saying there should be a substantial difference in temps. I'm also going to run whatever live data my scanner will give me, hopefully it has the O2 data in there somewhere.
Joe
Joined: Feb 2014
Posts: 20,492
Likes: 15,273
From: Crossroads of America
Joe,
When you aim your infrared thermometer to measure exhaust temps, be sure you are aiming at the cat body or the exhaust pipe immediately adjacent to the cat, and not the heat shield, or you will get a false low reading.
Off the top of my head, you are looking for an outlet temp of at least 100°F / 38°C greater than the inlet temp. You will need to let the engine run long enough for the cats to heat up to operating temperature. And be very careful not to touch the cats - the oxygen sensors don't even begin operating until the sensor temperature reaches around 600°F!
Cheers,
Don
When you aim your infrared thermometer to measure exhaust temps, be sure you are aiming at the cat body or the exhaust pipe immediately adjacent to the cat, and not the heat shield, or you will get a false low reading.
Off the top of my head, you are looking for an outlet temp of at least 100°F / 38°C greater than the inlet temp. You will need to let the engine run long enough for the cats to heat up to operating temperature. And be very careful not to touch the cats - the oxygen sensors don't even begin operating until the sensor temperature reaches around 600°F!
Cheers,
Don
Last edited by Don B; May 11, 2025 at 10:09 AM.
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
While I'm waiting for time to get out to the garage and do all of the above I've been searching the old interweb regarding vacuum leak detection methods. Anyone have any opinions between a smoke detection method and propane, butane or other spray products? I have a smoke machine and I'm thinking it's a bit safer. I have fire extinguishers but I don't want to find out what my reaction time is and how long it takes me to grab the extinguisher, pull the pin, and put out the fire. I'm not real big in singed eyebrows either, although my wife does complain they're too bushy.
Joe
Joe
Joined: Feb 2014
Posts: 20,492
Likes: 15,273
From: Crossroads of America
I have not had much luck finding air leaks or vacuum leaks using flammable gasses or aerosol liquids on Jaguar V8 engines, even while watching fuel trims, so I use a smoke machine. But the first thing is to perform a visual inspection for any oil seeping past gaskets or O-rings. If oil can get out, air will be inhaled under engine vacuum. Common leak points are the camshaft cover gaskets, spark plug tube seals, convoluted wye hose, variable valve timing solenoid gaskets, oil filler cap & filler neck (if equipped),
I have had a great deal of luck with smoke machines. The thing to know is that you must inject smoke into several points to test different parts of the system. I usually start by detaching the air intake pipe from the MAFS and removing the MAFS & air filter housing. I detach the air intake pipe from the throttle body and use something like a short wooden dowel to prop the butterfly valve open, then reattach the air pipe to the TB. I use a large rubber cone attachment to inject smoke into the air filter end of the air pipe. I'll run up to about 10 psi when testing the air intake. If your smoke machine is regulated to 1 psi for testing the EVAP system, it may not find leaks in the air intake. I look for leaks in the convolutions or accordion folds of the air intake pipe (very common), the convoluted breather hose from the air intake pipe to the right camshaft cover, the air pipe connection at the TB, the convoluted wye pipe, the intake manifold and gaskets, oil dipstick 0-ring, etc. If I'm satisfied that no leaks are apparent, I remove the dowel from the butterfly plate and reattach the air pipe to the TB.
Next, I will remove the oil filler cap and use a smaller rubber cone attachment to inject smoke into the left camshaft cover, then reinstall the oi cap and inject smoke at the part load breather hose port. Then detach the full-load breather hose from the right cam cover and inject smoke there. Plug the air intake pipe at the MAFS end and inject smoke into the brake booster vacuum pipe, etc.
I'm sure I'm forgetting something, but the basic idea is to study all the areas where air or vacuum leaks could affect engine performance/air-fuel ratio and figure out how to inject smoke in ways that tests as many of the seals and potential leak points as possible.
Cheers,
Don
I have had a great deal of luck with smoke machines. The thing to know is that you must inject smoke into several points to test different parts of the system. I usually start by detaching the air intake pipe from the MAFS and removing the MAFS & air filter housing. I detach the air intake pipe from the throttle body and use something like a short wooden dowel to prop the butterfly valve open, then reattach the air pipe to the TB. I use a large rubber cone attachment to inject smoke into the air filter end of the air pipe. I'll run up to about 10 psi when testing the air intake. If your smoke machine is regulated to 1 psi for testing the EVAP system, it may not find leaks in the air intake. I look for leaks in the convolutions or accordion folds of the air intake pipe (very common), the convoluted breather hose from the air intake pipe to the right camshaft cover, the air pipe connection at the TB, the convoluted wye pipe, the intake manifold and gaskets, oil dipstick 0-ring, etc. If I'm satisfied that no leaks are apparent, I remove the dowel from the butterfly plate and reattach the air pipe to the TB.
Next, I will remove the oil filler cap and use a smaller rubber cone attachment to inject smoke into the left camshaft cover, then reinstall the oi cap and inject smoke at the part load breather hose port. Then detach the full-load breather hose from the right cam cover and inject smoke there. Plug the air intake pipe at the MAFS end and inject smoke into the brake booster vacuum pipe, etc.
I'm sure I'm forgetting something, but the basic idea is to study all the areas where air or vacuum leaks could affect engine performance/air-fuel ratio and figure out how to inject smoke in ways that tests as many of the seals and potential leak points as possible.
Cheers,
Don
Last edited by Don B; May 12, 2025 at 08:27 AM.
Senior Member
Joined: Jun 2023
Posts: 666
Likes: 318
From: La Habra
While I'm waiting for time to get out to the garage and do all of the above I've been searching the old interweb regarding vacuum leak detection methods. Anyone have any opinions between a smoke detection method and propane, butane or other spray products? I have a smoke machine and I'm thinking it's a bit safer. I have fire extinguishers but I don't want to find out what my reaction time is and how long it takes me to grab the extinguisher, pull the pin, and put out the fire. I'm not real big in singed eyebrows either, although my wife does complain they're too bushy.
Joe
Joe
Senior Member
Joined: Jun 2023
Posts: 666
Likes: 318
From: La Habra
Morning Y2k,
Well if it turns out I do need a new cat or cats I'm just going to get rid of the car. Number 1, I don't want to spend $2,000 + for a pair of new C.A.R.B. cats and 2/ I don't feel like spending another weekend removing the old ones and installing the new ones and then asking the new Pope to say a mass that it works. I probably could install Non C.A.R.B. cats given that the little station I take it to never looks at anything but the OBD2. I've taken at least 3 cars there over the last few years and all he does is plug in the scanner and print out the info and take my money. But that leaves 2/ installing the new cats. In the words of George H. W. Bush, "Not gonna do it".
Joe
Well if it turns out I do need a new cat or cats I'm just going to get rid of the car. Number 1, I don't want to spend $2,000 + for a pair of new C.A.R.B. cats and 2/ I don't feel like spending another weekend removing the old ones and installing the new ones and then asking the new Pope to say a mass that it works. I probably could install Non C.A.R.B. cats given that the little station I take it to never looks at anything but the OBD2. I've taken at least 3 cars there over the last few years and all he does is plug in the scanner and print out the info and take my money. But that leaves 2/ installing the new cats. In the words of George H. W. Bush, "Not gonna do it".
Joe
Joined: Feb 2014
Posts: 20,492
Likes: 15,273
From: Crossroads of America
In addition to @Don B 's advice, I use a can of brake cleaner. Spray at the base of the intake manifold at each cylinder. Spray on top of each injector. Spray on the vacuum pipe connectors on both sides of the throttle body elbow and the one at the rear of the TB itself.
Cheers,
Don
Veteran Member
Joined: May 2009
Posts: 12,076
Likes: 3,361
From: home
Look at your fuel trims when spraying around the engine. The old time way of looking for an engine stumble just won't happen. Try it and see. I have. The problem is these cars adjust so fast to rich and lean conditions the only symptom you can see and follow are the fuel trims.
.
.
.
.
.
.
Senior Member
Joined: Jun 2023
Posts: 666
Likes: 318
From: La Habra
Look at your fuel trims when spraying around the engine. The old time way of looking for an engine stumble just won't happen. Try it and see. I have. The problem is these cars adjust so fast to rich and lean conditions the only symptom you can see and follow are the fuel trims.
.
.
.
.
.
.
Thread Starter
|
Senior Member
Joined: Oct 2024
Posts: 455
Likes: 82
From: Orange County Califorina
Thanks everyone for the tips, suggestions and encouragement. Today is babysitting day with the 2 year old twins (it was their birthday yesterday, and their almost 1 year old cousin, her birthday is next month. So, no auto work will be done today. It exhausting enough chasing these 3 around.
I'm going to give both the smoke machine (mostly because I just bought a new one and hate to see it go to waste) and the flammable spray methods. I'm going to be doing fuel trim checks anyway so I'll run the cable to the outside and keep an eye on them while I spray.
I'll be checking out the temps on the before and after areas of the cats to see what kind of info I can get from that. Hopefully there will be a big enough difference indicating that the cats are ok.
With any luck one or more of these tests will point to a solution that will not cost $2,000 or more to fix, and won't require hours of fiddling and knuckle scraping.
As I anticipate a good outcome to all this I've been checking out some additional improvements I should probably do including new plugs and coil packs. Any recommendations? I'm looking at Denso or NGK. Is about $75 per coil seem reasonable?
Joe
I'm going to give both the smoke machine (mostly because I just bought a new one and hate to see it go to waste) and the flammable spray methods. I'm going to be doing fuel trim checks anyway so I'll run the cable to the outside and keep an eye on them while I spray.
I'll be checking out the temps on the before and after areas of the cats to see what kind of info I can get from that. Hopefully there will be a big enough difference indicating that the cats are ok.
With any luck one or more of these tests will point to a solution that will not cost $2,000 or more to fix, and won't require hours of fiddling and knuckle scraping.
As I anticipate a good outcome to all this I've been checking out some additional improvements I should probably do including new plugs and coil packs. Any recommendations? I'm looking at Denso or NGK. Is about $75 per coil seem reasonable?
Joe