NOTE the sensor quote =

P1035 Jaguar Possible Solution:

Excessive air inflow can be caused by a vacuum leak, a dirty sensor or, an exhaust gas recirculation valve not closing properly. If the problem is not enough fuel, the culprit may be dirty injectors or fuel filters, a weak fuel pump or a leaky fuel pressure regulator. The lean fuel mix error may be accompanied by rough idling, engine misfires, hesitation during acceleration and overall poor engine performance

NOTE bank 1 quote =

Common Causes of Jaguar X-Type C0081 OBD2 Code

A common cause of code C0081 is the failure of Ignition Run/Start Circuit Short To Battery, but there are several other possible causes as well, such as ;

• Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
• Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
• Faulty variable valve timing (VVT)
• Improper ignition timing

 

Posts by "Brutal", a sort of demi-god of Jags, member years ago were a P0420 code you replace the catalytic converter. In the interim period to present, many members have had success just changing the sensors. Some tried all kinds of catalytic converter cleaner additives and the only ones that seemed to work were BG 44k & Restore (3x) brands which are fuel system cleaners and additives.

 

Thank you so much for the great relief with info that there are only two catalytic converters, which was the only thing I knew. This "mechanic" tried to play me after taking my money for a diagnostic fee. Not only I looked ignorant to him and an easy toy but I had (blasphemy!) a Ja-Gu-Ar no matter if x type. As for the P1035 I found the info that it can be because of a dirty sensor or an exhaust gas recirculation valve not closing properly at P1035 Jaguar Auto Trouble Code With All Car Models | Auto Trouble Codes - AutoTroubleCode.com. The rocket scientist mechanic explained (in writing) that Jaguar x-type C0081 OBD2 code was sign of a "failing ABS". I however read at C0081 Jaguar X-Type OBD/2 Code - C0081 Engine DTC Code : Ignition Run/Start Circuit Short To Battery | Engine OBD2 Trouble Codes that possible causes, beside failure of ignition run/start circuit short to battery, could be air fuel ratio sensor 1 bank 1 harness open or shorted or air fuel ratio sensor 1 bank 1 circuit poor electrical connection. As from all this mechanic illustrious illustrations is clear that he hates my car, I start being afraid that he might have sabotaged some circuits underneath my car as well. Whom should I trust? The one who lies, or another one who says "I don't touch your car, as it is a Jaguar."? There is a Ford dealer around who wanted to diagnose my car but his statement that his diagnosis could take the whole day also scare me. Shouldn't I start with changing the sensors of the two with a more modest guy?

 

marcela: For peace of mind, most large auto parts stores will read your error codes for free. Write down the error codes and post them here.

A few questions to help us help you:
+ I presume your check engine light is on all the time, but not flashing, yes?
+ Is your ABS light also on? (on the tachometer, ~8 o-clock position, "ABS" inside a yellow circle)
+ Any error message in the text box below the speedometer?
+ Does your X-Type run well? If 'no', what are the symptoms?
+ How many miles?
+ Did any repair or accident occur about the time the problems began?
+ I presume it's a 2.5L or 3L gasoline engine, not a diesel, yes?.

The so-called "mechanic" who says your X-Type has 5 catalytic converters must have huffed too much carb cleaner.

 

Dear Sir,
I tried my own amateurish luck with a Foxwell301 and the only DTC showing is P0420. The engine light is permanent (started after the great guys from a NY Jaguar dealer changed my battery after it died during the harsh PA winter) I don't have ABS light on but the great PA guy who told me I have 5 cats wrote in his report that I do have ABS failure problem because my code C0081, no other error message in the text below speedometer, Mona (her hame) runs well, no symptoms, she is almost 78000 mi old, she had a body part repair of her driver side mirror after a great PA fireman smashed my car while passing her by trying to reach a fire two properties away (I live in the woods with flammable trees), she is a 3.0L. Mona did not have an accident, but the lady x-type Jag before her had (actually I did have) a black ice patch whirling projecting me --and her-- against a tree in the woods 4 years ago which accident did not cool down my loving this type of car even if what I got instead from the money from insurance (Mona) was a used car that I did not know too much about except that she was 62k at the time. So she only has 2 cats? I was terrified by the idea of disconnecting the battery if I wanted to replace the sensors from the sad experience with her first battery demise (they say that you need to disconnect the battery if you want to replace the sensors). When I had Angelica (the TransAm 72 before moving to PA woods) I had no problem with getting underneath her or inside her engine compartment. But I was much younger at that time. And less timid than I am now. Thanks a lot for your answer, especially confirming that Mona only has two cats.

PS: Ah, and also: The great 5 cats mechanic also said in his report beside C0081 --ABS malfunction indicator:
2AA01H/10753 --undocumented code/ not found in service information system;
Bank 1 downstream 02 sensor very active indicating failing catalyst;
Upstream sensors display amperage and downstream display voltage.

 

marcela: Nothing amateurish about a Foxwell 301. And most of us recall back "when I wore a younger man's clothes."

Mona's ABS light is off, so her ABS seems to be working properly. The only indication of an ABS problem is from a mechanic who thinks Mona has 5 catalytic converters. Every car I've worked on since the 70's has 1 or 2 cat's, so who are you going to believe, a goofy "5 cat" mechanic or Mona's ABS light which is off? Just for grins, turn Mona's ignition key from off to the run position without starting the engine. The ABS light (and many more lights on the instrument cluster) will turn on for a few seconds, then turn off. This confirms Mona's ABS light works and is off all the time except those few seconds before you start her engine, when she does her diagnostic check of the dash lights.

Mona's P0420 code could be a few issues. Catalytic converters sometimes go bad, but more often it's a simpler, less expensive problem such as a bad oxygen sensor. Try a few things:

+ Mona's bank 1 cat is between the engine and firewall. Her bank 2 cat is between the engine and radiator. P0420 points to a problem with her bank 1 cat - the firewall side. The 2 oxygen sensors for the bank 1 cat have electrical connectors mounted on the firewall next to the brake master cylinder (on our US left hand drive cars). Confirm those 2 electrical connectors are plugged together properly. Pictures of these electrical connectors are in post #5, page 1 of this thread: https://www.jaguarforums.com/forum/x...4/#post1084230

+ Reset / erase Mona's error codes with your Foxwell scanner and drive Mona as you normally do. If / when the check engine light turns on again, read the error code with your scanner, then reset / erase it again. Do this several times over a few trips, and look for a pattern to the error code. Is it always P0420? Does it occur under certain driving conditions, e.g., when the engine is cold, or at highway speeds? Let us know what you find, and we'll try to help from there.

 

OR, quit putzing around and just replace the sensors (based on the codes already posted). THEN if it shows back up, it is for sure the more expensive and time consuming catalytic converter replacement.

 

I would like to change the Bank 1 O2 sensors myself because I start having doubts about bona fide of the mechanics around me but I don't know if I can do it without disconnecting the battery which disconnection is a problem for the Jaguars. Also can I do it without removing the manifold (Jac once said that he could do it)? Finally which ones to buy? The Downstream sensor is an oxygen sensor but the Upstream sensor is a A/F sensor and not all brands have A/F sensors.

 

Good Lord, I learn new things, thanks. The illustrious mechanics told me that the catalytic converters are ON the exhaust pipes underneath the car, not in the engine compartment. I looked at your splendid pictures, and inside my car, but I am still not sure where this converter BY THE FIREWALL is. Boy, how easy was everything when I looked inside the huge void of the engine compartment by the time of my 72 TransAm when there were no harassing catalytic converters but nice carburetors with points to set and removal of the spark plugs was a breeze!... I am very intimidated by the cluttering inside Mona. And her various computers. Last time the light came back after one long RT to New York (about 300 miles) and a second time after 2 small trips of 20 miles each with easy 40-50mph rural speed.
I see down here "show your signature" What does it mean? And whose? Yours or mine

 

marcella: Your signature is "2007 X-Type" and "show your signature" is the option to display it at the bottom of your posts.

You describe 3 times when the check engine light came: once on a 300 mile highway trip and twice on ~20 mile, 40-50mph trips. Were these 3 'bad' trips close together, or were they spread apart with many 'good' trips n between when the check engine light stayed off. During the 3 'bad' trips, was the error code consistently P0420, assuming you had the Foxwell scanner handy to read and reset the codes each time?

What happens now when you drive the car? If you reset the error codes and check engine light, does the light turn on again and the error codes return the next time you drive? Or does it take many trips before the check engine light turns on, and is the error code always P0420?

I ask because I'm not yet convinced the real problem is the bank 1 catalytic convert or the bank 1 oxygen sensors, particularly if these 3 'bad' trips were far apart.

 

I will scan again and show you what the scanner says. I might be wrong in how to handle this tool. Meantime let me know if I must disconnect the battery if I want to replace the sensor/s. Thank you.

 

marcela: I've replace oxygen sensors sometimes with the battery connected and sometimes with it disconnected. You don't have to disconnect the battery if you leave the ignition key in your pocket to ensure no one powers up the electrical system or starts the car while you're working on it.

There's no harm if you disconnect the battery. After you reconnect it, a few features will reset to factory settings, e.g., A & B trip odometers will reset to zero, odometer will reset to km, interior temperature will reset to degrees C, and the clock will reset to 12:00. The windows will need to be reset for the one-touch feature, if you use that: for all 4 windows, press the down button and continue holding after the windows are down for a few seconds until you hear a click. Repeat by raising all 4 windows up and holding the up bottoms a few seconds longer until you hear the click again.

If the goofy "5 cat" mechanic told you to replace the bank 1 oxygen sensors, I would first check the error codes before changing them. That mechanic can't be trusted any farther than you can throw the 5 catalytic converters he claims are on your X-Type.

 

Dear Sir,
I am very confused by these two readings of my scanner: P0420 and listing of shortly explained problems listing :CAT - OK (see attached and clear my puzzled mind please). As per the mechanic's advice, Mona needs "no whatsoever repairs of the cats and their 10 sensors because in PA we do not have emission inspection requirements", "you just cover the engine light with a black tape". It is ME who wants the sensors replaced. I apologize for the unplanned size of the two photos.

 

Is that guy that told you that an actual professional mechanic with an actual shop open to the public? If so, tht is a real shame, Warning lights come on for a reason. If it is operating outside the normal parameters it means something is wrong and will only get worse if it not addressed. If it is the catalyltic converter, fine. Replace it if it comes to that. However, before going to that extreme it is worth looking at the O2 sensors first based on other issues people on here have had.Much easier and cheaper than replacing the cat. Just a mystery on why you aren't getting any other codes usually associated with the P0420, which are usually the O2 sensors and misfires. Without knowing the history of the car and what may or may not have been replaced in the past it is hard to say. Could have been something like there weer severve misfires long enough to dmage the cat and those things were already addressed, but by then the damage to the cat had been done. Good luck with Mona.. Wish I could help more, but I can tell you are determined to get her fixed up once and for all. Members on here will do their best to help. This is probbably the most helpful, friendly forum of any car make or model on the web.Hang in there.

 

But this is even why they misinform me: they simply hate my car and want to sabotage it. Now that you tell me about replacement in the past, I am even more confused by these certified mechanics. Indeed they busied themselves last year with Mona and that was the reason to trust them this year too: Mona had engine light on last summer too and at my first encounter with the 5 cat mechs they (said that they) replaced her spark plugs and two ignition coils because she had the misfires. I forgot about that because she did not have any problems after that first encounter with them except for the problems with her battery during this horrible PA winter which the Jaguar dealer guys addressed via a $600 "Jaguar" battery and advice for a "mandatory" replacement of my cabin air filter (via a proposed $800) and nothing else. A, yeah. Living in the woods, her engine compartment is a huge attraction to chipmunks which I scare away with moth ***** and critter rider spraying but God knows? When I told them that I agree to change the cat with problems they said that my Jaguar car is not worthy the price of the (5) cat/s of which one they cannot know which is the culprit. I am very upset with all these people taking advantage of me and laughing at my car. You are right, this forum is very friendly. Thanks for encouragements.

 

marcela: Many mechanics are reputable, but your "5 cat' mechanic doesn't fit that description. This forum will help you steer clear of laughing mechanics and $800 cabin filters.

Under the hood, our X-Types look more complicated and intimidating than your 72 Trans Am, but the basics haven't changed. I learned on a 68 Plymouth Fury.

The advice of the "5 cat" mechanic to cover the check engine light with black tape is as foolish as Pennsylvania's chipmunks. If the check engine light remains on all the time, you have no warning when additional error codes occur. He's also wrong to say Pennsylvania does not require annual emission inspections - it depends where in Pennsylvania the car is registered, because the Federal Clean Air Act requires annual emission inspections in most urban counties: https://www.dmv.com/pa/pennsylvania/emissions-testing .

To replace the oxygen sensors, you don't need to disconnect the battery. Simply keep the ignition key in your pocket so no one can start the car or turn the key from the off position to the run position while you're working on it. Some people disconnect the battery just to be safe, so it's a personal preference, but not a requirement either way.

If you want to try replacing the oxygen sensors to see if this clears the P0420 code, I'd replace the downstream sensor first - it monitors the health of the catalytic converter. The upstream sensor monitors the air / fuel ratio in the cylinders, so a problem with the upstream sensor likely would cause additional error codes.

Post #14 in this thread describes how to replace the bank 1, firewall-side, downstream oxygen sensor without removing the intake manifold: https://www.jaguarforums.com/forum/x...4/#post1892379

 

Thank you so much. I will look now for the 3/8" socket wrench and a Bank 1 downstream O2 sensor. Which one do you recommend? Bosch lists 23" wiring harness overall length, NTK -- 21.8", Denso -21.26", Walker -- 21.65"

And please, why does the scanner lists "CAT - OK"? What does this conflicting info with P0420 mean?
Thank you also for letting me know about PA emissions rules. Here the 5 cat mechanics were however right: indeed emissions inspection in the rural/woody PA area/county where I live does not apply.

 

$600 battery and $800 cabin air filter? I don't even know what to say about that other than it is basically stealing. Those are things you can buy yourself and install yourself in less than an hour. Wow!

If you had some severe misfires last year when the plugs and coils were changed and they were bad enough that the check engine light was flashing for a long enough period of time while continuing to drive teh car, that could have possibly damaged the cat. That could explain why you are only getting the P0240 code now. Would still be worth changing the O2 sensors first though.

 

However the engine light did not come after those repairs last summer but only this year after battery change (at a time when the Jaguar dealer did not notice any MIL). You are right, Jaguar dealers steal and because of this, the "little people mechanics" are jealous and scare me more in spite than sheer ignorance. They automatically label us as "rich" which is not (especially in my) case. I bought my first Jaguar x type because I liked her very much and because she was AWD not caring for the 45 degree my 1 mile dirt road covered with ice and 1 foot snow during winter as my TransAm had. After I missed death four winters ago smashing into a tree, I wanted the same car to replace her. Mona's color is however not white. I will start with changing the oxygen sensor (should I change both or only the downstream one?) after I know which one to buy (they have different lengths). Then... what?... The mechanics say that it cost $2500 to change the Catalytic converter. Should I understand from P0420 that it is the Bank 1 one?

And the chipmunks ARE a huge problem here in the woods where I live, my first Jaguar had a (her only except for the last terrible tree smashing) loss, the electrical harness in the first winter costing $1700 (covered by the insurance). Since then I keep many conteiners with mothballs in the engine compartment and spray with Critter rider. Thank you for your friendly advice.

 

marcela: Bosch, Denso and NTK are quality brands, frequently found in new cars from the factory. I'm not familiar with Walker.

21" - 23" wires are plenty long enough for our X-Types.

The sensors for our X-Types are (bank 1 & bank 2):
+ Downstream: Bosch 15936, Denso 234-4798, NTK 25607
+ Upstream: Bosch 15627, Denso 234-9029, NTK 25631

I suspect "CAT - OK" means the engine's computer - the ECM - has completed the test cycle for the catalytic converters. If you reset / erase the P0420 error code to turn off the check engine light (aka MIL - malfunction indicator light), the scanner will probably display "CAT - INC", meaning incomplete test cycle. After you drive enough for this test cycle to complete, the scanner will once again display "CAT - OK", and if the problem persists, the P0420 code will reappear, along with the check engine light.

As much as we miss your 72 Trans Am and my 68 Plymouth Fury, they didn't have onboard diagnostic computers to help us troubleshoot problems.