my buddy installed an aftermarket header onto his 02' SI and afterwards, it came up a CEL. we went to a local autozone and they said that they couldn't run the code but it seemed like it deals with air/fuel mixture. we checked for leaks, there were none at all. and the o2 sensors seem to be good also. anybody have any inputs as how we could get rid of the CEL/fix it?

 

ok A) a race header will throw one no matter what
B) A shorty will throw one with a test pipe
C) Reset the codes and drive again and make sure all plugs are snug and secure

 

You tend to run lean with a race header. Might have to do a reflash and retune

 

mechanical o2 simulator on rear o2 sensor will clear it

$20 on ebay

 

i'll have to check out that o2 simulator. thx! anyone have personal experience from those?

 

or you can make one for 3.95