Replaced my test pipes with the Hyper-Flow cats. With test pipes my exhaust really smelled. The new cats got rid of the obnoxious odor. It seems to have the same power it did with the test pipes and the sound is subdued with the cats obviously. Still sounds great with the Tubi. Fit was ok and it did take some work to get them to fit but not to bad. Does not generate nearly as much heat as the stock cats.