2002 gmc yukon codes: P0171 P0174
 

2002 gmc yukon with 5.3 threw these two codes the other day. About 110,000mi, new maf last year, serp belt last year, and a water pump at least 6 years ago.

Had a buddy read it, and popped codes P0171 and P0174. Lean on bank 1 and 2. He cleared the codes, going to drive it and see if they come back.

Has anybody dealt with these? and what fixed it? Any ways to test it, before throwing money and parts at it?

Thanks
David

Re: 2002 gmc yukon codes: P0171 P0174
 

possible intake gaskets leaking.if they are the orange ones change them to the new green ones.

Re: 2002 gmc yukon codes: P0171 P0174
 

Vacuum leak or dirty maf sensor.

Re: 2002 gmc yukon codes: P0171 P0174
 

When was the fuel filter changed last? That would be the first place to look seeing how both banks are showing lean.
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Re: 2002 gmc yukon codes: P0171 P0174
 

Um not sure, are you thinking the fuel filter might be clogged and its allowing the same amount of air, but less fuel, causing lean code.

Re: 2002 gmc yukon codes: P0171 P0174
 

Seen it before low fuel pressure could also do it.
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Re: 2002 gmc yukon codes: P0171 P0174
 

Ok, my buddy cleared the codes when he read it, an they havent come back yet. So we'll see, and it hasnt changed how it runs.