P0171 and P0174
 

OK, so finally got to take my newly fixed vehicle for a spin, and just for fun I thought I would put the code scanner on it. I had no CEL but there where to codes in the computer, P0171 System Too Lean Bank 1, and P0174 System Too Lean Bank 2. Could this be caused by the leak I have discovered on the intake plenum, causing too much air to be mixed into the system?

RE: P0171 and P0174
 

Most likely. If the CEL is not on, they were just remnants of the problem you were having and will go away on their own. You could reset the PCM to clear them as well. It is your choice.

RE: P0171 and P0174
 

As Kyle said...I would make a mental note of these codes and clear. Time(and driving) will tell if they ever come back-doubt they will. Jerry

RE: P0171 and P0174
 

Well, I havent fixed the intake leak yet, and I did erase the code only for it to come back, but no CEL yet.

Hey. Uhm i have the same problem with my 96 Blazer and today i took it to my mechanic. he told me that the O2 Censors Might Be The Thing But im Not Sure About It.. Some Other People Tell me Its The MAF Censor Too But Im Not Sure Either