Alright now don't laugh too hard... Since the engine needs some back pressure (in exhaust) to operate correctly, and the Lancer (for some reason) has 2 cats, Would those cats supply enough back press. to eliminate the muffler (on bobo stock mitsu exhaust) and loose power. Would there be any gain? I do agree it would sound like hell

 

I would imagine that you would gain HP, lose some low end torque, plus, it would sound like crap...

Someone correct me if im wrong

 

im sure it'll do waht crazy said..but it'll be loud as hell
-Bob

 

There's a difference between backpressure and making it hard for the engine to breathe. While the cats make it harder to breathe and add backpressure, removing both will only improve performance (say, full exhaust and manifold) as long as you're able to increase the amount of air entering the engine.

 

I removed my cat and mufflers and gained like 20 hp. However my exhaust backfires. Am i getting back pressure yes and no. My car is still doing better performance wise and i have an auto so you it doesn't back fire while driving, and if i throw it in neutral while driving it sounds nice and deep.