Planning some modest modifications for my 4.2L exhaust. Not really looking to drop $1500-3000 for a few HP.Mostly being a poser and looking for a little more rumpity, especially at idle. Thinking I'll probably delete the main muffler and install apair of aftermarket straight-through resonators in its place.

I'd like to have an H or X crossover installed with high flow cats as well, but I've been told that the car may through error codes or a check engine light. OF course, that was from a vendor for those upscale systems. I searched posts and got mixed results, does anyone have experience with this or a solid expectation whether or not replacing the cats will cause 'issues' for the 4.2?
THanks

 

I just removed my cats and had vast make me a X pipe and install flowmaster mufflers. Vast makes a ELE it will stop the CEL for the no cat issue in your car
it is about 1/2 way down the page
http://www.vastperformance.com/products/exhaust.php

See the vid link in my sig to here how my exhaust sounds

 

Thanks! too open for my tastes, I'm getting old I guess. And I'm a little too green to go catless on my daily driver. Did you do any before/after dyno tests to check the results of the x-over and cat delete?

A decent crossover can produce a decent amount of power on the 928s, the cats less-so as the factory designs are getting harder and harder to improve on (in performance vehicles, at least). I have a magnaflow internal-x dual in/out muffler that I was going to install in lieu of cats on my 928, but I think it would be noisy on the Audi and I'm not sure if there is adequate clearance, and I don't know thatit would build a ton of power especially if I don't do much with the rest of the exhaust system.