Hello people!

I'm getting system too lean error codes p0171 and p0174 on both banks.

2000 xkr 4.0

I have check the air duct for leaks, removed and cleaned MAF, and reset codes, start the engine and yank the MAF wire loom to see if there is a short somewhere to no success.

The pattern is always the same. I clear errors , and after 10 motorway miles or so , the engine light comes on, and restricted performance message comes up briefly, then goes away. Codes remain in memory.

I feel nothing mechanical in the engine or performance affected , no noticeable change at all when light comes up.

What would you check next?

Thanks

Mariano

 

Here is a part load breather leak link :
https://www.jaguarforums.com/forum/x...e-part-219539/

 

When you clear the DTCs, you do NOT clear the stored adaptation.
The LTFT and STFT do NOT start from zero with a simple DTC clearing.

I always remove the fuse for the ECM to clear ALL adaptations as well as clear DTCs with a 'code-reader'.

This method will start everything from ZERO when you read the fuel trims after repairing or replacing a component.

 

Best would be to do a smoke test to find out if there are air leaks, which are very common on an aging car.

Best of luck, keep us posted.

 

I had to remake the PCV breather hose. The guy before me tried to do it with one hose, but the angle for the plugs got messed up and it leaked through the connectors. I used heater hose (5/8") and two 5/8" brass 90 degree elbos to make a hose that fit better. Use the original blask plastic connectors, too. That got rid of the "too lean" codes for me, and cost about $30 and an hour.

PCV breather comes out of black disc on lower right, goes left past thecylinders, thendiwn and into the rear of the engine block.

 

Would this apply to the XKR with the Supercharge?