My 2001 XJ8 has a check engine light with the following codes:

P0174,
P0443,
P1000.

Can anyone with experience help me out with what needs to replaced?
Or even the best place to start.
I'm pretty savy with cars basically but jags are completely new to me.

Thanks in advance

 

Well, I don't know what P443 is, and P1000 is only a drive cycle indicator, but P 174 is a lean fault. On these cars, the most likely root cause is a split part or full load breather tube. Those are the tubes that run from the valve cover to the air intake system. Look carefully for a aplit. Another common air induction leak is into the plenum that reuns from the air cleaner to the throttle body. Again, look CAREFULLY for leaks. You did not mention any misfire, but a misfire, bad MAF, bad inlet air temp, aexhaust leak before cats are all also mentuioned. But I would look at the breathers and the plenum first, second , and third!

 

sparkenzap, thanks for the knowledgeable reply. i have a good place to start. currently working long days won't be able to look at it until friday. but i'll be sure to keep up post on what i find.
by the way, is there a shop manual you reccommmend for this car. i looked on line and there seems to be very little from haynes or chilton. the only one i could find was a six vol $1000 version.

thanks again for a starting point.
chris

 

chris:
As to the shop manuals, none are real good, but there is a software manual called JTIS. Look here: https://www.jaguarforums.com/forum/s...t=9933&page=26
It takes some getting used to, but the archives will give you some info.
In addition to JTIS, I use alldatadiy.com, which is a subscription service which costs about $30.00 a year as I recall.

 

443 appears to be an EVAP purge valve control malfunction. Cause listed as bad wiring/connection or bad valve. Since this is fuel system related, I wonder if taking care of this might clear up the lean problem?

 

Ross-- my chance to learn. Do these kinds of vacuum leaks often cause only one bank to show the lean fault? I assumed it would trigger the fault on both sides. For that matter, I guess I'd expect a fuel system problem to trigger the fault on both sides too. Just curious. Thanks!

 

Well, you would thnk it would be on both sides. I had only one side code as I recall. The other side will probably code if driven further. And, I copied the most relevant pinpoints from the shop manual.

I doubt the evap fault would cause a lean code. That indicates the tank vacuum is not holding, spewing all of that polluting gasoline vapor into the air we have to breathe. That can also be a cracked hose on the evap system. Or a loose gas cap.

 

Cleaning the TB, Breather stub and the MAFS will help and you should look at the air filter and replace if necessary. As for a leak in the vacuum system and only getting a code for one side is possible, I have seen stranger things. The attached links might help. http://www.gusglikas.com/images/Auto...J27%201999.pdf http://www.gusglikas.com/images/Auto...otos/P0171.pdf

 

well this weekend i did some trouble shooting and reall didn't find much wrong. however what i did learn.
first off i have three codes
p0171
p0174
p0443

basically both banks or lean and i have trouble with the egr system.
i searched all the vacuum line in the engine compartment and all looks ok. i still need to find the vacuum line and canister for the egr system and not sure where it is. any help.

is it possible the gas cap could be the culprit. it seems corrodes and doesn't look to well

also can anyine tell me how to trouble shoot the egr valve and system.

thanks,

chris