ok so ive had a cel light for a while my car runs really rich because of it. i took it up to autozone to have them check the code and its a p0138 they didnt have an exact description for the code though.They said its probably my catylatic converter or something. they wernt very helpful but does anyone actually know what it is and what i need to do. thanks alot!

 

maybe a bad O2 sensor???, my cars check eng light is on cuz my rear O2 sensor is bad and runs rich but im not totally sure if thats ur problem

 

Rear o2 sensor has a high circuit voltage! Replace your down stream o2, and you should be set! Cat would come up as Cat failure, or low effecientcy code, which is not po138... cat code is p0420!!

 

Forums -> Help forum -> 3rd thread from the top



NEVER guess or trust the monkey reading a scanner at Autozone.

 

ok thanks alot. which 02 sensor would i need to replace? the one thats under the car? and how would of this happened any way, just incase if theirs anyway to prevent it agian.

 

Down stream 02 looks to be your issue, there for it is the one right after the cat, the one you would have to lay down to see under the vehicle. Also there is no way to prevent it, you have to think about it, there is alot of heating and cooling, and that to me seems stressful, I would say it is probably the stock one from the factory and it is just getting old, things break and get old... Mechanically object are like us humans, we wont last forever.



fix that sensor, and you should be rocking and rolling!

 

Test it with a blow torch. http://www.youtube.com/watch?v=vdn4Dk5PSwc