bypass tubes vs oxygen sensors
 

What happens when you bypass or remove the primary cats. what do you do with the oxygen sensors? Does the engine check light come on? How does a person deal with that issue?
Tks.,
MR.G.

If you remove the primary cats, you will need to place the O2 sensors somewhere close to or in the headers, if replacing the stock manifolds. Unless you race the car, I think trying to fool the system isn't worth it. I removed my secondary cats and installed bypass pipes in their place. No CEL and zero problems when emission testing time comes around.