Take away the smell? I was going to weld an XR-1 into my midpipe, but I figured I could put some flanges on a cat and then put flanges on the extra pipe as well. That way I could drive around with the cat in, but put in the straight pipe when headed to the track. The thing is, how well do the high flow cats reduce the exhaust smell?

 

I can only speak from my personal experience with my Gotham Racing Hi-flow cat, but it really did help out with reducing the exhaust smells. Whether it helps in terms of providing a power increase or not, I couldn't tell you. I put that on my FD with a lot of other mods before I took it to a dyno.

 

They reduce it just fine provided you have an airpump and its working. Switching from the stock cat to the Bonez cat, I incurred no extra "fumes".

 

I have the Pettit HF. No smell at all.