I've got a manic stage 1 tune, and I just picked up a used, catted DP. The DP has a catted spacer in the lower O2 port. Should I remove this when installing on my car, or will it not hurt to leave it in place?

I understand that the Manic tune will supress the CEL.

I appreciate any advice.

Have fun,
Mike

 

Stage 1 will not suppress the O2 sensor code, only Stage 2 and up.

 

There's no harm in leaving it even if you had a tune that suppressed the CEL. The engine only uses the pre-cat sensor for how it judges fuelling and the post-cat is only there to check if the cat works.

 

Yes it will. I went Stage 1, installed a catless DP and didn't get tuned for weeks. Never got a light. If I went back to stock tune I would get a CEL though.