So i have had some c\cels pop up over the last few days. One day last week my cars DIC said "check gas cap". Then i had a light. Well, autozone said i had 6 cels. 1 was a gas cap and some lean codes and a few others i dont remember. I replaces my car and cleard the codes. Anyway i have some new ones toay....

P0137 HO2S Circuit Low Voltage Sensor 2 ECM, PCM
P0172 Fuel Trim System Rich ECM, PCM
P0496 Evaporative Emission (EVAP) System Flow During Non-Purge ECM, PCM

Anybody know what these are trying to say. I dont know how my tune could change if it did? I no its rich because my wideband says "Rich" at WOT. But, it wasnt rich and ive been tuned for a long time now. I have changed nothing on my car.

 

Are you also experiencing the dreaded idle problem?

https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/idle-problem-cure-finally-116051/

 

If ur running rich, the easiest thing to check first is ur air filter. Esp since you've been tuned for a while and are just now having the problem. Clogged filter=less air=rich lol That EVAP code I'm not too sure on, that's a tricky system to deal with.

 

i just put on a new filter. and my idle is fine. I have cleaned my MAF and throttle body. I have a K@N filter and hydro shield.

 

hmmm....retune? Your rich code is prolly being thrown by whatever it is causing that evap code. You didn't recently install an underbody kit did you?

 

no i didnt install anytihng. Im thinking about replacing my evap solenoid.

 

I had an underbody kit installed once and the dipshit that did it ran the screws right through my rockers and into the wiring harness that ran through there. It just so happened to ground out an evap system wire and threw my cel. But since that isn't the case for you, I would call up a dealership and ask one of the techs what the possible problem could be for those codes. That's what I did and that's how i found out about the stupid screw in the wiring harness.