I drive my Evo very light on the street, I use it most for track duty, my question is this, should I be concerned about the CEL due to the pipe, or should I get a hi-flo cat to leave on it just in case. I hate to drive hundreds of miles to and fro the track, with the CEL on?

Thoughts?

 

The insufficent catalyst code that it will set wont hurt anything. mine has been on for about 800 miles now. I got the rear o2 simulator that I havent installed yet which should take care of it though.

 

I dont like check engine lights. Ultimate Racing cat delete works well(no light) if you connect the extension wires from the o2 sensor properly. If you dont have UR test pipe, fabricate a spacer in your rear o2 thread so that the sensor is not fully exposed to the exhaust flow, this will trick the sensor.
good luck.