1997 1500 Po175 And Po172

[khebert]

i have a 1997 gmc 1500 xc with a 305 180,000 miles and everytime i drive the truck i get the pending codes of po175 and po 172 (bank 1 and bank 2 rich) and after the truck is turned off and restarted these same codes are set and the check engine light is on. i have the cfi and have cleaned the injectors changed the pre-cat o2 sensors, fuel pressure regulator. the truck runs fine even when these codes are set just the mpg goes in the dirt. i am at a loss

[joeyross]

It could be a faulty fuel pressure regulator or a dirty air filter, or distributor cap- rotor- wires-plug problem. If a fuel pressure test indicates 60-66 psi with the key on- engine off and doesn't drop after the pump quits I wouldn't think it would be a regulator problem

 

is there any kind of misfire from it?

can you sniff the tb and see if you can smell gas from the top of it? if so....

i believe you have the spider injector assembly and it is made out of mostly plastic. you could have a small leak coming out of the bottom of it or in one of the nozzle lines.

 

after checking the fuel pressure i would start thinking about pulling the plenum off and re-attaching the fuel lines then turn the key to get the fuel pump on but not the engine and see if there are any leaks if so its time for a new injector assembly. a pretty easy fix but costly.

good luck

[Duelin]

It could be a faulty fuel pressure regulator or a dirty air filter, or distributor cap- rotor- wires-plug problem. If a fuel pressure test indicates 60-66 psi with the key on- engine off and doesn't drop after the pump quits I wouldn't think it would be a regulator problem

 

is there any kind of misfire from it?

can you sniff the tb and see if you can smell gas from the top of it? if so....

i believe you have the spider injector assembly and it is made out of mostly plastic. you could have a small leak coming out of the bottom of it or in one of the nozzle lines.

 

after checking the fuel pressure i would start thinking about pulling the plenum off and re-attaching the fuel lines then turn the key to get the fuel pump on but not the engine and see if there are any leaks if so its time for a new injector assembly. a pretty easy fix but costly.

good luck

 

 

Also check you MAF sensor. It could be the problem seeing that both banks are affected.