[Rickology]

So I just purchased a new PE from BMW dealer in cali. I removed my secondary cats and welded a piece of stainless steel pipe from the catless downpipe to the PE. I then decided to use the clamp to attach the muffler and the downpipe.....I think this is where the issue is. I'm not sure I installed that stupid clamp right.

I'm thinking about welding the muffler to the downpipe, before I do...Anyone have any thoughts or ideas? Has this happened to any one else? Did I install the clamp wrong? I'll take a pic later on tonight to show how it's installed.

[Chrispy650]

Back when I had my PE w/ secondary cats removed it was all clamped on. I didn't have any rattling issues or anything. Maybe check the clamps and make sure they are tightened. I am sure that's the issue. You can always weld everything together if you want but I mean I had the same setup as you back then and didn't have any problems.

[Volasko]

Not that it answers your specific question, but when I installed my PE the install shop said the clamps where better than welding because the weld naturally rusts.

[Bmachine18]

The rattle may be coming from something losse on your exhaust when I installed the magnaflow catback dual exhaust on my 328 I installed it my self and I left one of the bolts loose then it should be so I heard the noise after putting it on a lift it was oviously the loose bolt

[Rickology]

Thanks guys, yeah I've retightened the clamp and nothing. Noise only happens at about 2k rpm when the cars cold. After it warms up can't really hear it anymore. I'll have to put it on a lift and check it out.

[Onefreakinuserid]

Lift it up, loosen the whole system, realign the whole system so there is plenty of clearance from any possible "obstacles", and then retighten. It could be as simple as hitting a heat shield.

[ntpcrew13]

I had the same issue. Check the exhaust hanger that bolts up to the back on the transmission. Mine would rattle when the car was in drive but at a stop or when going kinda slow.

[E90-07]

I had the same problem kinda when i installed my pe, it would rattle near the back of the car if i was like accelerating and making a turn... go check the back of your muffler there should be this little round rubber can that bolts onto it... I'm sure thats what its there for cause the second i put mine on it stopped

[NBK]

you have a clear exhaust leak. not sure how your car has a downpipe, but if you prepare the area of pipe where the 2nd cat was deleted, the weld will not rust.

mine are still holding without clamps, and those clamps aren't very effective anyways.

[Gjm127]

Any updates? How's the sound?

[Rickology]

Originally Posted by Gjm127

Any updates? How's the sound?

Haven't had the time to put the car on a lift. I'm going to allocate some time today at my dad's shop to see if I can check all the bolts closely. Hopefully i'll find out what's causing it, if not i'm going to end up welding the muffler to the downpipe

[csupernova]

at first I had the same problem too. Rattling noise when RPM below 2k. Turns out the clamp was touching the plate which is in the middle of the car. The plate is held on my 8 screws. It should be easy to see. Try to check on that. Good luck.