I have a 97 3800 NA 198 K total( junker engine with 19k at 108 k) changed LIM about 20k. I am getting an intermittent 0171 code and last a day or so each time. I have cleaned MAF. Any other suggestions?

Thanks for the help,

John

a few things can cause the lean code, beside the o2 sensor, any unmetered airleak, vaccuum after the maf

P0171 is NOT an O2 sensor. Please do not suggest changing it, please understand teh o2 is reading the lean condition.

Generally it'* a vacuum leak, unmetered air will cause the lean condition. I have also heard that a bad connection at the battery can also cause this code. P0171 is the hardest code to track down.

I have a 1997 SEE with 159,000 miles on it. I changed the engine at97,000 and replaced it with an engine that had 56,000 which means the engine has approx 118,000 miles on it. I have had the check engine light and P0171 codes for a couple of months now. I recently left the code reader plugged in while driving , and have discovered the code comes on shortly after starting the engine , but as I cleared it out while driving, it doesn't come back on as long as you are driving without shutting off the engine. I had the engine tuned with a new fuel filter from the tank, new wires and plugs. Still same problem. I just recently removed and cleaned the MAF sensor, the Throttle position sensor, and the idle sensor. The idle sensor was very carboned and wasn't sealing the hole completely at all. After cleaning and replacing ll of them, I cranked the engine and drove approximatley 20 miles without a code or check engine light. I shutoff and restarted without either. then after starting and driving about 5 miles, the check engine light came back on. and it was the two P0171 faults again. But, after clearing them with the engine running, they dont come back as long as driving. The engine starts and runs smoother now since the cleaning, but the fault is still reapperaing after starting. HAvent checked the ground connections yet. What would the start up have to do with it , without reappearing as long as the engine is running?

I found out what was causing my problem. It was the gasket that seals the plenum to the intake. The 2 round gaskets next to the stove pipe had become the consistency of jello. They must have been attacked by something and were obviously failing. Went ahead and replaced the lower gasket also while I was in there. Have only had one recurrence of the 0171 since then and I believe that is due to a fuel issue that I am dealing with but that is a subject for another thread.

Good to hear you found it.

Just for info sake, I finally found the problem causing the P0171 code reappearng.
While driving with the code meter pugged in, and finding that the light would come on shortly after cranking , then after clearing with the meter while driving, and not reappearing as long as the enginewas running, I had the fuel pressure checked and found it to b low causing the PO171 code to appear when the oxygen/fuel mixture was too lean. After the pressure built up while the engine was running, the code wouldn't reappear.
I got a new sending unit, fuel pump, and sock. Very expensive, but did solve the problem. Car cranks very well and the code has not reappeared.