mick wrote:How do you tune a resonator by placement? They are welded in. My muffler resonates at 2,600 rpm and I can't stand the sound.
You can tune the sound by how close the resonator is to the muffler, the closer they are, the deeper the sound in most cases, I've seen some cars with one under the cabin and another b4 the muffler
And to answer the cat question, they don't pollute much more, some aftermarket cats are WAY better than stock, and your stock one is probably shot by now anyways. I'll tell you one thing, it's 1000x's better than not running one at all, and helps with the sound even