Do the header fit with the ACV still on? I don't wanna be farting around this wekend and find out they need to come off. I need the ACV on for emissions testing.

tia

 

They will fit with the ACV on, but it will be useless and you wont be able to pass emissions with the header anyway.

 

Unless you have a strict visual check like CA then a header will pass just fine, it has nothing to do with emissions anyway. What cat are you going to run with that header? the stock one won't work, at least not as it is. I have a RB header, and miller performance 3 way cat (the one sold by mazdatrix as grey market) and it passed with flying colors back in the fall.

 

I have the RB header with a custom 3 way cat already bolted to it. Just goes right up to the connecting pipe/muffler.

Our emmisions is visual for cat and tailpipe sniffer. They are not concerned with headers.