Discussion Starter · #1 ·
I've looked this up on multiple forums and haven't been able to get ONE consistent answer to this question which I thought would've been fairly easy to find. I'm looking to make a custom exhaust for my 97 540 and I want to install an X pipe right after the O2 sensors but I want it to clamp on so I can access the driveshaft if needed. I know the factory exhaust clamps on at that same position and realoem says those clamps are 55mm which is 2.165", so is the exhaust pipe coming from the cat 2" and the piping going to the rest of the exhaust slightly larger or is exhaust coming from the cat 2.165" and the exhaust clamped to it smaller? Or are they both the same and butt connected. I ask because I'm sure you all know but there aren't exactly a variety of options at 55mm for exhaust components.