well i have a testpipe on the car with a 2.5 exhaust system all the way out . it set off the check engine light on when i put the test pipe, i am guessing its the o2 sensor. the car feels like its gonna stop running sometimes rough idles but then it goes away until i stop at a light again. anyone ran in to a problem like this and know how to fix this stiuation?? thanks guys

 

Did you use the non-fouler's when installing the O2's?

 

wow thats the first time i hear that what is the purpose or what is it?

 

they move the 02 sensor out of the mainstream.. and prevent the car from throwing a check engine light via secondary 02

search for anti-fowler mod

 

that wouldnt cause your engine to be lazy though. only the front one can be related to running issues if its bad. double check all your vacuum and boost connections around the airbox since that had to be taken out to get the test pipe in.

 

The 90 degree spacer (Wayne Schmidt from VW vortex) works well with a HFC (not sure if it works as well with a test pipe). No CEL since I installed it (I was getting CEL's just about every day).

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