[simplyeric]

Just recently upgraded my stock 330i exhaust to an M Performance 340i Exhaust about a month ago, but after doing a small tire check and lifted, the muffler has a very big black spot on the middle of my muffler. IT looks like a huge burn mark.

Not exactly sure what this is, and would love to know if this is normal?

It seems like the specific area has already a pre cut out square around the area.. Is this something that I must maintain?

[HarryTee]

I don't have the M-Perfornance exhaust, so can't check it out for you but from your photos, it doesn't look like something to worry about, but is part of the construction of the muffler.

[simplyeric]

Originally Posted by HarryTee

I don't have the M-Perfornance exhaust, so can't check it out for you but from your photos, it doesn't look like something to worry about, but is part of the construction of the muffler.

Hey man, thanks for the reply. Yeah, hopefully I can get a few words from others. I would assume it's some form of soot, but I am not sure about BMW exhausts. It seems like there is a square lining around this specific area.

[Billfitz]

It looks like heat discoloration from welding.

[Scorp10]

Totally normal. Every MPE I've seen has it, new or used. I bought a new MPE for my car and it has the same weld mark, but the way it is installed you can't see it looking under the rear of the car. I attached my MPE for reference and circled the weld marks.

[simplyeric]

Originally Posted by Scorp10

Totally normal. Every MPE I've seen has it, new or used. I bought a new MPE for my car and it has the same weld mark, but the way it is installed you can't see it looking under the rear of the car. I attached my MPE for reference and circled the weld marks.

Uggg thanks a million. This is reassuring. Thought I was driving it too hard from the get go. Seems like it isn't an issue anymore now that I see this. I only noticed it when I actually lifted it. Thanks a million man!