Originally Posted by 01RangerEdge
Not really, exhaust and a single cat removal is about it, besides headers. I wish there was a way to replace all the cats with a single high flow cat and still make the O2 sensors read correctly
You can remove the catalyst(s) and make it pass emissions without any catalyst(s) whatsoever - I passed emissions today as a matter of fact in my IX with no catalyst at all - that being said my motor is built and costs more than your truck did when it was brand new.
That being said, unless you have a built engine, it will more than likely make your performance WORSE.
If you want better sound find a muffler and modify from the catalyst back for a sound you like. Changing the exhaust from the catalyst forward requires fuel and timing recalibration to work correctly inside the ECU ROM.