Hey guys, my 05 silv 5.3 cc keeps popping up these codes p0171 bank 1 lean and p0174 bank 2 lean. I have superchips w/ 91 tune, headers, exhaust, tb spacer, slp 160, cold air intake, and mass sensor, and ported throttle body, and 4.10's. normally ill get the occasional p0102 when i have a intake leak, but never had these codes. Thought it might be because i changed the plugs, but they were stock replacement. Pulled the a couple plugs from each side and they looked like they were getting hot, pinkish. I have a set of 31lb injectors i could throw in, would this help, or are plugs the problem. seems sluggish of line, but picks up the same higher rpms. any help would be appreciated.

 

My money is on the MAF... Do you have the stock one to put back in and test with?

 

whats the deal.... this is the third lean post today including mine...

 

check your fuel pressure and fuel pressure regulator, if you pull the tube off the regulator only air should come out, if you have gas coming through the tube replace the FPR

 

New at this, is the FPR on the fuel rail, black and chrome?

 

whoops, just realized that you have an 05, your regulator is in the tank sorry!

 

do check your fuel pressure though!

it can be an exhaust leak as well or clogged injectors ,O2 sensor failed
or something with the tune or possible MAF issue

 

i bet its the maf sensor, put a gms sensor on my cousins 05 5.3 and it was sluggish down low and couple days latter got the same codes put his factory maf back on and his low end picked back up and the codes haven't came back

 

thanks man, i had it on for almost 30,000 miles and now i am getting the codes, but would that make the plugs run lean though?, its not pinging, knocking nothing, just doesnt smoke em off the line anymore, when i got the 4.10's it will light up through second, hope thats the prob. thanks

 

It does have a exhaust leak at collector though, not to big but has one, ill check that too i guess.