headers and high flow cats
 

I want to buy some of those ebay headers without the catalytic converter and weld high flow cats into my Stebro test pipes that replace the second set. Can I hook one sensor to the O2 bung on the header and the second to the high flow cat in the rear? Will this eliminate the CE light problem? Anyone done this successfully?

I've looked into doing the exact same thing with catless headers and my FabSpeed exhaust. Problem is, you're probably better off just buying high flow cats that fit. The cats themselves are not cheap, and once you factor in custom labor to weld them into your test pipes, you more than likely won't have saved anything and had a bunch of lost time and added frustration.

To answer your second question, yes, moving the secondary O2s to be in line after the high flow cat should eliminate the CEL and let you pass a smog test. Hypothetically, at least.

Patrick