hey guys, couple weeks ago i got "service engine soon" light on (20k miles on the car and never seen it on before), 2600 miles from last oil changed. so i pulled the code and got P1870 and P0420, then i changed oil but the code still there. 1-2 hours after the oil changed, the code disappeared by self (normal??) and never came back on until yesterday i got the service engine soon light on again. today i pulled the code, P1870 and P0420 again. what happened?? i got Ultimate Racing METAL HFC a year ago and car was tuned more than 6 months, everything was fine and even now i don't feel anything different. local guy told me maybe the CAT was bad...

note that couple days before i got the first service engine light on, i went to a crappy gas station (lowed tank so i have to.., filled up half tank of 92). is it possible there was water in the fuel and fxxked up the CAT?

thanks~!

 

you have this posted in the wrong section...try the "general" or "engine/drivetrain" forums.

 

try this 5 dollar fix. works great.

https://www.evolutionm.net/forums/ev...ouler-how.html. this should get rid of the p0420.

the other code is related to transmission slippage, at least according
http://wiki.answers.com/Q/What_does_the_code_P1870_mean

 

thanks, i already re-posted

 

the transmission works fine and i hope it is not the tranny..