[lm1z]

Originally Posted by Teutonic M3

After reading all the opinions here, it became clear that all good X-pipes have an X and a pair of resonators. Well, since factory M3s already have an X and a pair of resonators, the only difference is that the factory X-pipe has a pair of secondary cats.

I know this has been done before here, so since the secondary cats have nothing to do with the CEL lights, I decided to remove them the old fashion way - long drill bit and a crow bar. Then I had two 5 cm long extensions welded onto the pipe ($25) so they would slip over the OEM down pipe. Done.

I doubt anyone makes an X-pipe (no matter how pricey) that gives you any real HP gain over this set-up. Whole thing took about 2 hours.

Who can beat $25 and OEM look and quality?

Good solution if you don't need to replace your OEM pipes in the future. I guess you could always buy another stock pipe if needed, but I wouldn't want to go through the trouble.

I've never been a fan of modding OEM parts. With a car this expensive I want what's on my car to be done right.
I'm a big fan of R&D, build quality and weight savings.