[M3to335]

Im going to have a shop cut out my second cats, replace it with a test pipe and then weld in flanges to the stock exhaust. The idea is to be able to have the stock catted section of pipe bolt back in when I sell the car, bring it in for service, or go get the emissions done.

My questions are these;

1) Where should I stop with the new piping? Im going to begin right at the downpipe flanges. Should I end before the x, or after it?
2) If after the X is there any advantage (or disadvantage) to running 2 seperate pipes all the way back?

Thanks,
Scott

PS_ if you have pictures of your own setup, that would be much appreciated.

[mayno]

if it's a reputable exhaust shop, I would ask for their recommendation on where is the best locations to bring it back to stock as easily as possible.

noticed you went from m3 to 335...I did the same. had the e46 m3 and got the 335, and I don't regret it. wow, you're getting a 135 as well? hope you got a good deal on it.

[M3to335]

My wife drives the 135....its a blast! We picked it up in Germany so it was a deal good enough not to pass up

I will ask their recommendations as well, but its always good to hear feedback from folks who have already done it to this car.