2006 Chevy 4.3 P0171,p0174,p0420

[jethro66]

Hey guys I have a 2006 chevy c1500 4.3v6 4x4 with these codes p0420 p0171,p0174.I cleaned the maf senser installed a new thermostat witch was stuck open and did a throttle body cleaning.truck runs great but the exaust sounds really noisy when cold onstart up I cleared the codes but after the 2nd driving cycle they come back up.The truck has 110000 miles.

[txab]

Well since those are lean codes,have you checked the fuel filter and fuel pressure?

[gmtech4]

exh back pressure test to Darral? would that cause a lean code ? a fuel guy should chime in because i am not a fuel guy lmao !!!! i am a trans/driveline guy !!

 

intake gaskets?

 

my apprentice gets to yard out an Allison for a torque converter seal and pump bolt seals lmao ,i will help only verbally ..... hehe hehe !!

[txab]

exh back pressure test to Darral? would that cause a lean code ? a fuel guy should chime in because i am not a fuel guy lmao !!!! i am a trans/driveline guy !!

 

intake gaskets?

my apprentice gets to yard out an Allison for a torque converter seal and pump bolt seals lmao ,i will help only verbally ..... hehe hehe !!

+1 on the intake gaskets.

 

Was having trouble posting last night, added that in an edit and guess it didn't ever get posted.

[jethro66]

Oo

exh back pressure test to Darral? would that cause a lean code ? a fuel guy should chime in because i am not a fuel guy lmao !!!! i am a trans/driveline guy !!

 

intake gaskets?

my apprentice gets to yard out an Allison for a torque converter seal and pump bolt seals lmao ,i will help only verbally ..... hehe hehe !!

+1 on the intake gaskets.

 

Was having trouble posting last night, added that in an edit and guess it didn't ever get posted.

 

Ok thanks for the replys It looks like its gonna be a costly repair