P0171

Interested in this. I was halfway through a 2500 mile road trip last week hauling 1800 lbs of payload (four wheel camper and gear). Cruise control downshifted from 4th to 3rd on some big hills and thats when it first happened. Had it cleared, continued driving carefully from then on and it came back. Still on for a whole day of driving and into the next day, then it disappeared. No issue 1300 miles since. It must mean something though, I am curious what you find.

 

How long does it take for the EVAP system and O2 sensor to complete its test after clearing codes by disconnecting the battery? I disconnected it after I cleaned the MAF sensor and the throttle body about two days ago.

 

02 sensors should run after a good 20-30 minutes tops on the highway

Evap can take a couple days, fuel level has to be between 25% and 75%..

If the 02 sensor monitors won't run that can be a sign one of them is bad..

 

So the P0171 code is back so took it to the shop and said it is very likely that the fuel pump is going bad. After I left the shop the CEL went away again. So I'm still going to change out the fuel pump assembly. This along with the rear wheel bearing which is causing my Break and ABS light to go on. Yay....