[s2d4]

Originally Posted by Target70

I don't think there would be a delay. If the O2 sensor before the cat does all the A/F calculations, then you leave it where it is, and you don't have any delays. If this is correct: "The second O2 sensor is literally only there to ensure your cat is working", then all you have to do is weld in the bung behind the secondary cat, and move that second O2 sensor from it's factory, "after cat/second" location, to the new third location, with the help of the o2 extension cable, then plug up factory "after cat/second" bung.

I have done a little research and even with the antifouler or mini-cat method, some people still have problems with CELs. This seems like a good way to run a catless header and avoid a CEL with no tune, or if you need to flash back to factory tune. The only problem I see is that I have heard that the sensor has to be at an angle, something about condensation causing premature sensor failure if it is not angled properly, and secondly is if cat doesn't get hot enough. I don't think we will have that problem, but it's nothing some header wrap wouldn't fix.. IMO.

You must have forgotten he is extending both o2 sensors.