Hey MBWorld!

Wanted to share a quick story from earlier this week that had me freaked out and fearing the worst...

I drive an 09 C63 with MBH headers catless into xpipe. I was performing a heavy pull in 2nd gear off a light when I heard an extremely loud pop (almost like an explosion) immediately followed by my car sounding like crap. I have given the car plenty of hard pulls and never experienced anything like this. I did not see or smell any smoke, and no dash lights appeared, but the car was making a really nasty kind of hatching sound under any sort of load.

I quickly found a safe spot to pull over and decided although the car "runs", I did not know what happened and feared the worst. I called up my insurance to dispatch a tow truck as I was about 45 minutes from home or my local indy. I scanned MBWorld forums in the meantime for anyone with a similar experience, with the fear that I may have seriously damaged my motor.

I was not finding anything and figured speculation on the issue was only adding to my stress. Within 30 minutes the tow truck driver arrived and he had the right wooden boards to prevent my car from scraping (absolutely necessary with the carbon front lips...). Got their owed to my local mechanic who had every parking space and bay full. I was told they did not have any availability for the next two weeks, but "maybe" we can look at my car in a few days..... They were swamped! One of the mechanics heard my car and told me to check the exhaust for leaks. At the same time I had also sent a video clip to a very knowledgeable m156 tuner who said; "big exhaust leak".

I live around the corner so babied my car home and put it on some ramps to inspect the exhaust. Long story short, the exhaust where the catless pipe section connects to the xpipe was completely disconnected from the other pipe.

I HAD BLOWN THE EXHAUST CLAMP RIGHT OFF THE XPIPE! The clamp was likely shifting over time and was just waiting for the right pop or pull to break loose. Not totally sure why it happened but a couple new exhaust clamps did the trick.


Where the "cat" pipe meets the X with clamp blown off


It was a dark few hours between the tow and actually finding the issue. I am extremely grateful that my issue was simple to find and cheap to fix.

Anyways, sharing my experience to document what happened... don't be scared, check your exhaust for leaks before thinking the worst.

Happy riding!

-C63Dave