I could be wrong on this, so please no flaming, but if you have a cutout before the o2 sensor, it should throw a code, when its open right? And when you close it, it should go away? Maybe this could be explained by someone with more exhaust knowledge than myself. I'm thinking of running a catless DP, and deciding on getting a cutout as well.

 

it wont go away when you close it. the engine must be started 3 times with nothing setting he code (aka dont use the cutout for 3 engine starts) and the CEL will go away. I would say just get rid of the CEL in a tune.

 

Well granted I didnt think it wold actually just go away when closed, figured when shut off then restarted, it would go away. Did not know it took 3 starts. Still want to keep warranty, so tune would be out of the question. Still waiting on GM kit. If it's not released then tune by Trifecta will more than likely my choice.

But regardless, I'm right about throwing a CEL. Thats all I wanted to know. Thanks.

 

Considering an "O2 chamber" is being used by many of us, the manufacturers, to help prevent a code, with the cut-out open the reading at the sensor wont change much. Not all of the exhaust is going to empty through the cut-out. A large volume will still travel through the exhaust.

 

Excactly - since to run catless you have to have a tune or a "chamber" you wont have an issue with a cutout. (Thinking about Hahns Modpipe?)

 

ehhh, just deal with the CEL on track days, restart 3 times... seems easy