Have you tried unplugging the cable to the MAF sensor? If the code clears when you do it's the MAF sensor, clean or replace it. Other possibilities are; as mentioned in my previous post, contaminated fuel. You might try adding a fuel drier product like HEAT &/or changing gas stations. Also check the connections and wiring to the PCM and its ground, and O2 sensor connections and wiring. Could also be an exhaust leak, fuel injector(s), clogged fuel filter or fuel pump strainer, or low pressure from the pump itself. Have you had any stalling or hesitation? Do you have a scan tool capable reading sensor current values? If you do, I have the factory service manual and can tell you what those values should be.

 

I have been trying to get the fuel pressure checked,and my friend that owns a garage wont change the fuel filter cause the connection is rusty and it looks like its gonna open a can of worms,new maf and new o2 sensor,when I hit the gas it flys ...put good gas in lucas octane booster, special additives for injectors put zmax in to try..was very free ....lol can try unplugging the maf after the light goes back on,i shut it off fri morn.

 

How may miles on the engine? Have you replaced the pesky plastic LIM gasket with an aluminum one yet? If the gasket leaks it could cause coolant to leak into the combustion chamber.

 

It had a headgasket replaced little while ago it runs fine.. I unplugged the maf and cleared the code .. Now what drive it till it comes back on? I got a p0204 i think it was for voltage on maf i believe

 

p0102 code it is,low voltage,as to be expected with the plug off..90k on motor...do I wait to see if p0171 comes back?

 

P0204 is "Injector 4 control circuit". Did you clear code P0171 with your scan tool or did it clear itself when you unplugged from the MAF? As I understand it, and I encourage anybody out there to correct me if I'm wrong, by unplugging the MAF it puts the system in "Closed circuit" mode and P0204 code should not appear unless there's a problem with the injector or it's wiring.

 

yes I cleared codes and unplugged the maf and got the p0102 not 204 that was a typo

 

Don't clear the code. Wait to see if it clears itself

 

Well now its unplugged and its still at the 102 code,I will plug it back in and start from scratch..no codes... when it comes on ,how wil I know if it clears,the light will stay on cause of the maf being unplugged..

 

Was the 171 code there when you unplugged it? If it was and only the 102 code comes up after unplugging it's probably the MAF. You should still get the 171 in addition to the 102 if it's not. The PCM would still sense the lean condition in closed loop mode and throw the code. The quote from the factory service manual checklist regarding P0171 under diagnostic aids is: "Mass Air Flow Sensor- Disconnect the MAF and see if the lean condition is corrected. If so, replace the MAF". The only way to diagnose further is with a scan tool capable of reading fuel trim values, like a GM Tech 2. BTW don't leave the MAF disconnected and drive around for very long.