Please help!!!
I have a 1995 XJS 6.0 V12 convertible with 36,000 original miles. The check engine light went on and I am getting a code F44 on the trip computer with the key in the on in the second position. I had both oxygen sensors replaced and within 3 days the light is back on and the F44 code is showing on the trip computer again. Any help would be much appreciated.
Thank you,
Steven

Submitted by stevejag@sbcgl… on Tue, 07/05/2011 - 23:22

Steve,

If your FF44 is really that sporadic, testing like I described may not be conclusive. It is still worth the effort though, because it MIGHT give you and indication. I always test both banks to compare, because they should be very similar, if all is copacetic. If they are not, that is something to go on.

Good luck!

Submitted by stevejag@sbcgl… on Mon, 06/27/2011 - 08:51

Steven,

Fuel fail 44 is for a fault detected in the "A" Bank [right side] oxygen sensor. It doesn't have to be the sensor itself, it could be something driving the sensor to either a lean or rich limit. That means it could be a vacuum leak as George suggested, or it could be something like a failed fuel pressure regulator causing excessive fuel pressure. That would make the system rich instead of lean. Even a fuel injector spraying too much fuel on that side could cause it. You might pull the hood off of the oxygen sensor connector for the right bank, and check it with a voltmeter while it's running. When all is well, the voltage will bounce up and down between .1v and .9v. If the voltage stays at .1v you are lean, like a vacuum leak. If it stays at .9v, look for excessive fuel.

Good luck!