i ahve the cel on so i decided to check the codes and i got 0304 0901 0315 then i reset the ecu and decided to check again just to make sure so after i reset it and checked the codes i got 0505 which is no failure decoded. how come the same codes didnt come up. thanks for your help

 

Because you erased them. They won't show up again until you driver the car a few times.

 

thanks for the info but can some1 tell me what the 0315 code is cause its not defined in the sticky. Thanks

 

0315 - Downstream oxygen sensor high voltage fault.

You either have a bad cat or a defective O2 sensor.

 

ok i got one more question so i ahve been driving with a day and a half since i reset the ecu and the lights havent come back one....my question is since the CEL is not on does my car think everything is fine in particular is it out of the safe mode that knock sensor codes causes cause if it is my car doesnt feel like it has its old "pep" like before this whole ordeal with CEL started happening.

 

take it to autozone and have them check the codes if you cant figure it out