Etylorcen

Does it matter where the o2 bung is installed? Does it need to be right in the cat or can it be on the piping after it? (Primary o2 sensor ob2)

inspyral

Primary needs to be before the cat, secondary goes after the cat.

Etylorcen

Damn it what the hell am I thinking the primary is on the stock header. I meant hte secondary...does it have to be inside the cat like the oem cat is or can it be right after it.

inspyral

The OEM secondary is actually after the catalyst portion of the cat, so if you put it a few inches further downstream like you said, I don't think it'll matter much. The readings may not be as accurate, but the secondary O2 is just there to make sure your cat is working right anyway.