Own a 2004 S-Type 3.0 (non-Supercharged) with about 104,000 miles on it. Recently I have had a series of yellow lights, and have solved all the codes except P0174, which is supposed to be "System to lean-bank 2". I have recently changed both cats, all six plugs and all six ignition coils, and the upstream, right bank O2 sensor. Can anyone give me an idea what I need to do to correct the P0174 code? What does it exactly mean, and where should I start looking to correct it. I can clear the code, but it comes back in a day or two. Has anyone else had this problem?

Charleswoolsonjr
New Jersey, USA
2004 S-Type 3.0

 

I just finished fighting p0171 and p0174 codes. since it looks like you done all the major things. sound like a vacuum leak maybe the issue. believe it or check your gas cap. mine had no seal. Next please check you air hose clamps after the MAF make sure they are sealing correctly. If all is good here you may have a bad MAF. After i replaced my gas cap and checked my fuel trims that was closer to normal. recleaned my MAF once more and made sure all the clamps where tighten, within about 50-60 miles my check engine light went off and has not returned, it been about 3 days now with no light.

important allow the ecu to turn the light off itself. do not reset it after the repair. just put the ecu in a not ready state in most cars. When it cycles it comes back up in the state it was before, you will still have to go thru a drive cycle for the ecu to see the repair.

 

Welcome Charles this will help you out:
https://www.jaguarforums.com/forum/s...ics-faq-52720/

 

Check fuel trims - dozens of threads about them - and see whether or not you have an air leak. Post the figures if you need more help.

 

I was told to try replacing the gas "paddle /sensor" it could possible help fix the problem with the throttle position sensor in some of the s-type Jaguar series does not hurt to replace and adjust the sensor screws cheaper than continued trips to jaguar dealer.

 

That is likely to cause faults. There are multiple sensors for redundancy and the whole assembly is high precision. It is probably terrible advice. I would wonder whether the person giving it knew anything much about S-Types and not go back to them.

 

Follow JagV8's advice in post #4. I had the same issue awhile back, I have all gaskets and vacuum lines ( see joycesjag post also)on order. I am replacing all gaskets, o rings, etc from the cam covers up. ( while I'm there, coil packs and plugs will be replaced too, 86k miles). I also have leaking IMT o rings which will be done also.

Might be extreme, not cheap,but these things should be done considering the age and mileage of my car, and hopefully done for good for the life of the car.

Then its on to replacing all cooling lines, and the rest of my issues punchlist!

 

Had nearly the same problem, check this thread https://www.jaguarforums.com/forum/s...-codes-140300/

 

Based upon the advice I received, I checked the vacuum hoses, and found one which was off. After reconnecting the hose, the code resolved itself. Thanks for the good advice. My S-Type based NJ inspection today!

CharleswoolsonJr
2004 S-Type

 

Good news!