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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?
It's not a bad idea to replace the spark plugs. The original plugs in your engine may have been the NGK PFR5G-11 double platinums, but Jaguar subsequently superseded those to the NGK IFRN10 laser iridiums. A prior owner may have installed another brand or model of plugs, but you can't go wrong with the original NGKs.
If your ignition coils are original, they are probably high-quality Densos made in Spain. The new Densos are made in China, so unless your current coils are failing and causing misfires, you're probably better off keeping them as Y2KJag suggested.
OK, so I got a few minutes after my physical therapy session and went out and check the temps before and after the cats. I'm getting about 320 before and 300 after on both sides. This, from what everyone has been saying is not good . Is there any other way to determine that they are bad for sure? Shouldn't all the marvelous electronics, monitors and scanners be able to realize this and tell me something is wrong (other than the monitors not being able to reset)? According to the AJ-27 Engine Management guide I should be getting a P0420 and P0430 for a "Catalyst efficiency below threshold". I get none of those codes. I can't find anything in the instructions for the iCarsoft scanner telling me if it can give me this information but I'm thinking it should. Anyone out there have any idea what is going on?
The monitors not setting is the electronics telling you there's a cat problem. A far as it can tell, they're not hot, or they're not present.
I could be wrong but I don't think you'll get cat efficiency errors until the monitor sets. The monitor that would throw those codes isn't working yet.
You can verify by checking the downstream sensor voltages.
Well if the "monitors" can't monitor the catalytic converter until they reset and they can't reset because there "might" be a bad converter then this is the most absurd system of monitoring I've ever heard of. I can't believe that you the "system" won't show me I have a bad cat with the codes that it's supposed to use until I put in new cats so it can show me the codes. That sounds like what I'd hear from Louis Lugnuts and his traveling car repair truck. "Well, sir, your sophisticated computer can't do its sophisticated work until I spend a day, and charge you $4,000 to remove your maybe bad cats, and replace them with maybe cats that will maybe work. But don't worry, I guarantee all my work right up until you put the key in the ignition?"
If that's the case then this car deserves to be in a scrap heap.
Again the real problem you have is that you bought a car without a known history - the previous owners "repairs" could well have been a series of bodges to get it running/moved on to the next owner. The car's computer expects to have all the modules, sensors and (in this case) catalytic converters that it left the factory with. You have also done various hard resets, which wipe out all the monitors that were already set, erasing any working baseline you had. I don't suppose the engineers envisaged a situation where they would need to detect missing, as opposed to under performing, cats on a car with zero stored data.
You need to keep on testing, eliminating and replacing until you finally get it working - you will then have a known baseline of a working car making it a lot easier to diagnose any future problems. And I know it's too late now, but I would be very reluctant to do a hard reset in future when you need monitors set to pass inspection.
Right now you are chasing problems that may well be ghosts, you are going to eventually find something real and it will be the eureka moment.
On my car which is different (2014 XJR). I had catalytic efficiency errors. Same old ones P0420 and P0430 for passenger and drivers side as posted above. Without any monitors being set. I was constantly clearing the codes trying to figure out the cat problems. So I think the cat codes will be set regardless of the monitor status.
They really have to or how would you troubleshoot the car?
Yes a very good point from dibbit that should be mentioned every time you clear the codes puts you back to resetting all the monitors which is a pain.
Since you don't have cat errors I would forget them and move on. You don't appear to have bad cats.
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Again the real problem you have is that you bought a car without a known history - the previous owners "repairs" could well have been a series of bodges to get it running/moved on to the next owner. With all due respect to you much greater knowledge regarding these cars than I have I agree with part of this statement. The car I purchased does, in fact, appear to have had several items replaced, including the Transmission Control Module and the Engine Control Module, and possibly the catalytic converters. And I have replaced the downstream O2 sensors with, from everything I've read and been advised, were ones that are compatible with the car.
The car's computer expects to have all the modules, sensors and (in this case) catalytic converters that it left the factory with. Here I have a question. It sounds like you are saying that the "car's computer" will only work with the original equipment "it left the factory with." To me this means that no Jaguar will ever run properly with replacement parts. How can this be? This sounds like the car will only last as long as it has all original equipment. So if one of the monitors tells me that a part is malfunctioning, rather than replace the part with a compatible part I should drive it to the scrap yard. I have to be misconstruing your statement here. Perhaps because of my frustration.
You have also done various hard resets, which wipe out all the monitors that were already set, erasing any working baseline you had. I don't suppose the engineers envisaged a situation where they would need to detect missing, as opposed to under performing, cats on a car with zero stored data. I replaced the battery with a new one (rated at the required power for the car) at the suggestion of one of the members based on the series of messages I was getting on the dash. I'm guessing that reset everything and it also stopped the messages. I later did perform a hard reset (again at the suggestion of a member) in order to see if there was a problem that it would cure with the monitors not resetting. The cats are not "missing" they are right where they belong. Now they may be replacement cats but they are clearly the ones that were made specifically to fit on the car with all the mounting tabs and bungs for the sensors. I'm not sure why you're suggesting that part of the problem is that I'm trying to get a car with "missing" cats to work properly.
You need to keep on testing, eliminating and replacing until you finally get it working - you will then have a known baseline of a working car making it a lot easier to diagnose any future problems. And I know it's too late now, but I would be very reluctant to do a hard reset in future when you need monitors set to pass inspection. I am going to keep "testing", however, if the tests being done by the car's own systems do not tell me I have an improperly function catalytic converter by showing the codes associated with them what else would cause the before and after temperatures to be what they are?
Right now you are chasing problems that may well be ghosts, you are going to eventually find something real and it will be the eureka moment.
I'll continue to "test" in search of what could possibly be wrong with this car but without the car's systems pointing me in the right direction I'm, in the words of The Boss, "dancin' in the dark" .
On my car which is different (2014 XJR). I had catalytic efficiency errors. Same old ones P0420 and P0430 for passenger and drivers side as posted above. Without any monitors being set. I was constantly clearing the codes trying to figure out the cat problems. So I think the cat codes will be set regardless of the monitor status. I'm a bit confused by this. Are you saying that your OBD2 was showing the P0420 and P0430 error codes but all the monitors were showing OK? Or are you saying that the monitors would not clear because of the trouble codes? In either case what did you do? Did you replace the cats? Do you mean the "cat codes will be se(n)t regardless of the monitor status (but miss the "n"?
They really have to or how would you troubleshoot the car? My thoughts exactly. Isn't the whole purpose of all the computers and monitors and sensors to tell you where the problem is? If I'm NOT getting P0420 and/or P0430 what is the meaning of the temperature differences?
Yes a very good point from dibbit that should be mentioned every time you clear the codes puts you back to resetting all the monitors which is a pain. I agree here that when I clear the codes I will have to go through the monitor clearing process, the problem is that those 2 do not appear to clear.
Since you don't have cat errors I would forget them and move on. You don't appear to have bad cats.
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Can you think of any other reason for the higher temperature before the cats than after them?
Today's project, if the baby takes a long enough nap, is to check the fuel trims and maybe look for a vacuum leak.
To check the CAN bus has 60 ohms across it, you need to put a multimeter in ohms mode across pins 6 and 14 on the OBD connector by the driver's knee. The ignition should be off with the key out when testing this. Some forum members have bought themselves breakout dongles to make this easier, like this one (random example):-
The CAN bus working on not doesn't really impact on the O2 sensors as they connect straight to the engine control module, but I would still check it. It does seem that you are getting to the point where either you simply haven't driven the car enough to get the monitors to complete, or the cats are bad. There isn't much left to replace on the car now.
Just to make sure I'm testing the correct pins it would be the 2 pins that are third down from the top of this picture across from each other, correct?
I had some time to go back out and plug in the OBD2 again. I still get the same P1799, P1797, and U2500 faults. I'm also getting a U1135 (ignition state not obtained) and U1041 (SCP vehicle speed signal - invalid or missing message).
I also forgot to mention that there are no P0420 or P0430 codes on the OBD2. Also, I was not able to do the live data at any other speeds but idle. I'll go out later and do them again at 1,500 and 2,500 rpms. I did just get home from a short trip and took the temps before and after the cat on bank 2 and this time got about 450 degrees before and around 400 after. I could only reach under the car far enough to get to the lower part of the cat, which is where the bend is and the bracket mount is located, not directly at the O2 sensor area.
I had some time to go back out and plug in the OBD2 again. I still get the same P1799, P1797, and U2500 faults. I'm also getting a U1135 (ignition state not obtained) and U1041 (SCP vehicle speed signal - invalid or missing message).
Hi Joe,
Which module is reporting U1041? It's possible that could be related to your transmission issues. The U1135 probably has to do with a front seat or door module. U2500 is probably a CAN communication fault somewhere, but it isn't listed in my X100 DTC Summaries.
Also, it is very helpful if you visit your User Control Panel and Edit your Signature to add the year, model and engine of your car so that information appears in all of your posts. That way we don't have to scroll all the way back to your first post to be reminded of that information.
Which module is reporting U1041? It's possible that could be related to your transmission issues. The U1135 probably has to do with a front seat or door module. U2500 is probably a CAN communication fault somewhere, but it isn't listed in my X100 DTC Summaries.
Also, it is very helpful if you visit your User Control Panel and Edit your Signature to add the year, model and engine of your car so that information appears in all of your posts. That way we don't have to scroll all the way back to your first post to be reminded of that information.
Cheers,
Don
Hey Don,
Sorry about that. It's the security locking module. I believe it has to do with the trunk lock button on the back of the car. The trunk, sorry Boot, opens with the key fob and the button on the bottom left side of the dash, but not when I try the button on the back of the car.
I'm sorry I thought I fixed that User Control Panel thing. I'll go back and try again.
I'm reading this document from Jaguar regarding the drive cycle for the catalyst Monitor.
It indicates that the Catalyst Monitor drive cycle is to drive 31-45 mph (1,100-1,600 rpm) for 23 seconds with a Mass Air Flow of 5-30 g/s (.6-4 pounds/min.)
However, this document, from the Jaguar OBD Drive Cycle Readiness Notes, states that I need to drive between 1,700-2,500 for 5 minutes:
I had some time to go back out and plug in the OBD2 again. I still get the same P1799, P1797, and U2500 faults. I'm also getting a U1135 (ignition state not obtained) and U1041 (SCP vehicle speed signal - invalid or missing message).
I also ran the live data and got the following:
What do the two columns represent? The downstream O2 voltage in the left column is very low. In the right column they look more normal.
. Is there any other way to determine that they are bad for sure? Shouldn't all the marvelous electronics, monitors and scanners be able to realize this and tell me something is wrong (other than the monitors not being able to reset)? According to the AJ-27 Engine Management guide I should be getting a P0420 and P0430 for a "Catalyst efficiency below threshold". I get none of those codes. I can't find anything in the instructions for the iCarsoft scanner telling me if it can give me this information but I'm thinking it should. Anyone out there have any idea what is going on?
