Hello, it has been a while since my last visit to the forum.

My XKR has been running great for couple years, but as we know all good things must come to an end! now I have problem.

I have been getting consistent codes P0171 and P0174 which I know is caused by several different problems. Lean bank 1 and lean bank 2 I think this means to much air in fuel mixture, correct?

The symptoms are: the transmission light will come on and I will get a restricted mode at highway speed of 65 to 75 MPH but the car runs perfect no change even in restricted mode, yellow light appears, then the restricted will go out after I get down to street speed of 35 to 50 MPH yellow light goes out and restricted mode disappears but the transmission light stays on and does not go out unless I clear faults.

The one big kicker symptom is every now and then the car will just die, it seems to start right back up after stopping on side of road and even sometimes just coasting after placing in neutral and engaging starter and back into drive, but this symptom could be rather dangerous on the freeway at 75 MPH ! My battery is Brand NEW.

At street speeds usually no lights come on.

The whole time this is happening with warning lights the car drives just fine (except for dying, which does not happen often, is it even part of the problem?), but i'm sure internally something is not!

Can anyone give me a clear place to begin? I am no mechanic but would like to see what i can do if anything before it goes to mechanic and even then would be nice to give them a place to start. I thank you and appreciate your time and reply in advance.
Regards, Mitchell

 

Short version: you likely have air leaks. There is air going in the engine, and some of it bypasses the air flow meter. The fuel trim system catches it and adds fuel for you, up until there is just too much air (+25% fuel added). On an older car, everything connected to the cylinder heads can leak air. If the engine shuts off, the leak must be big at times. Check the big air intake tube from the air box to the throttle body. The corrugated section is known to develop cracks over time, especially from the bottom. Besides that, if you are not fixing yourself, you need to look into a smoke test: smoke is injected in the intake so that smoke can be seen leaking out from the problem areas.

Besides that, you can have a faulty air flow meter, basically giving the wrong reading. Might be worth trying to clean it with a dedicated spray to start with...

Best of luck, keep us posted.

 

See the attached document for the meaning of the codes you posted.

Link http://jagrepair.com/images/AutoRepa..._2001_OBD2.pdf

 

Thank you for the replies fmertz and Gus.
The problem turned out to be fixed with a new MAF sensor.
$545.00 to repair... ouch!

And remember to Drive Safe...

 

That is far and away the most expensive MAF sensor I have ever heard of....

 

SNG Barratt lists the MAF for the 4.0 SC cars for $237+. and if he took it to a dealer you'd expect them to run diagnostics and spend anywhere from 1 1/2 to 2 hours.




The cost for having a more exclusive car I guess.

 

The exact-match Denso MAF sensors can be ordered from amazon.com for less than $70. I purchased one back in February that works perfectly in both my S-Type and my wife's XK8....

 

The supercharged cars, of that vintage at least, use an all together different MAF and although SNG isn't known for the cheapest stuff on the block (or the most expensive either) I suspect that a garage capable of diagnosing non-ODBII codes will also get top dollar for the parts.

The MAF for my NON-SC'd 1999 with the very same Denso part# cost me $49 and also fits several years of Mazda and Subaru.


Expensive? Yes, but how many XK8's were supercharged and how many other such engine/intake combos like that exist in the wild today even counting non-Jaguar makes?