CEL--fuel system too lean. any experience here?
Posted: Tue Sep 11, 2007 2:45 amThe wife's EJ6 just developed this in the last month.
At the end of a four hour drive (the car ran perfect), we got off of the freeway and the engine stalled as we were setting at the end of the exit ramp. It restarted immediately, and ran great until the next traffic light where it stalled again as we sat idling.
At this point there was no CEL, and no other abnormal indications.
It was fine for the next week. Then after a two hour trip, the CEL came on. And once again the car started stumbling at an idle as if it was about to stall.
I read the CEL code, (OBD-II on her ECU) as a code P0171, for:
fuel system too lean.
Things I have tried:
-one bottle of injector cleaner with the last fill-up.
-verified gas cap on tight.
-cleaned off the MAF sensor (with alcohol)
-verified no bad seals or disconnected lines on the intake all the way to the throttle body.
I don't believe the O2 sensors or MAF sensor are bad, there would be a separate code for that.
It is getting worse than normal gas mileage. But the car runs great except occasionally when it idles, it stumbles.
Most of my friends are telling me I have a vacuum leak downstream of the MAF that I can't see.
Personally, I think the fuel filter is clogged, and that's why the stumbling only shows up when the car has been running for a while--the fuel line downstream of the filter is getting sucked dry?? am I out to lunch on that thinking?
In any event, the filter is easy to replace, so I am trying that next.
Any help is appreciated.
At the end of a four hour drive (the car ran perfect), we got off of the freeway and the engine stalled as we were setting at the end of the exit ramp. It restarted immediately, and ran great until the next traffic light where it stalled again as we sat idling.
At this point there was no CEL, and no other abnormal indications.
It was fine for the next week. Then after a two hour trip, the CEL came on. And once again the car started stumbling at an idle as if it was about to stall.
I read the CEL code, (OBD-II on her ECU) as a code P0171, for:
fuel system too lean.
Things I have tried:
-one bottle of injector cleaner with the last fill-up.
-verified gas cap on tight.
-cleaned off the MAF sensor (with alcohol)
-verified no bad seals or disconnected lines on the intake all the way to the throttle body.
I don't believe the O2 sensors or MAF sensor are bad, there would be a separate code for that.
It is getting worse than normal gas mileage. But the car runs great except occasionally when it idles, it stumbles.
Most of my friends are telling me I have a vacuum leak downstream of the MAF that I can't see.
Personally, I think the fuel filter is clogged, and that's why the stumbling only shows up when the car has been running for a while--the fuel line downstream of the filter is getting sucked dry?? am I out to lunch on that thinking?
In any event, the filter is easy to replace, so I am trying that next.
Any help is appreciated.
