I was setting my sights on getting a new cat-back exhaust for my evo but I am now thinking about a turbo-back system. the question is if I get a turbo-back system with a hi-flow cat instead of a testpipe will that throw a CEL? I heard thay if there is a Cat in place that it wont set off the CEL. Thanks for the help!

 

nope no cel.... the highflow will burn off enough of the excess fuel to keep everything in order

 

I would say no, but just last week my CEL came on. I got it check and it was ecu code 420 which would be the same one a test pipe would throw. I have had my hi-flow for about 8 months now and this is the first it happened. After I took the code out it has yet to come back. I don't get it.

 

your car has had its O2 recall performed correct?

 

How would you go about eliminating the cel?