OEM Exhaust rots through 12 months after replacement
 

I want to share my story here and get some feedback. The major failure occurred just today, but I have been hearing signs of this failure mode for about 4 weeks. It was only today that I had a complete failure, and I was able to identify the root cause.

This begins when my OEM exhaust was replaced in June of 2018. I ran over a large rock at the beginning of 2018 and it required my exhaust to be completely replaced. There was a dent somewhere, so the dealer said they needed to replace the entire thing because it was 1 piece. Fine.

I put a Borla ATAK axle-back on 8 weeks ago. 4 weeks after that I started hearing an air leak. It sounded like "ttssssss" as I apply very light throttle tip in. It wasn't there during normal driving. I thought I must have a clamp at the axle back that was not tight enough.

2 weeks ago, I started hearing a loud rattle from under the car. It happened mostly while driving at slow speeds through a parking lot, and especially when hitting bumps. I assumed it was related to the axle back again and I have been trying to find the time over the weekend to pick the car up and look at it.

Finally today. I am on the freeway driving normally and I suddenly hear a very loud rattle, and then my exhaust note goes from NPP Tour to straight pipes. I assume the worst so I get off the freeway right away and stop at a park-n-ride. I get under the car and I find this piece of metal hanging down under the pipe, still connected to one edge. I was able to get to a shop where they lifted the car and I checked under it. This little cross member piece has rotted through and we were able to pull it off pretty easily. I am left with 2 holes in the pipe just behind the cats.

So, what do we make of this situation? The exhaust was put on just 12 months ago. Should the dealer replace it? What am I to do? I cannot understand why it would have rotted through.

Also, does everyone recognize these materials as stock, OEM NPP exhaust? This middle section looks like an aluminized steel, according to the shop who looked under the car. Is that normal? The front section appears to be just steel? The original repair was covered by insurance where I get OEM parts. I want to be sure this was an OEM NPP that was put on.

Altogether, I am very annoyed by this situation.

Do you drive it in the winter when the roads are salted? The dealer "should" replace it but I would look into a better sounding aftermarket stainless cat back now but that is just me.

This exhaust has seen 1 winter season, from the end of 2018 through 2019. It is my daily driver.

Free cutouts lol

I wouldn't have expected that after just one season. I would just do an aftermarket one since you have to replace it anyway, sounds better and made from better materials.

I am debating on doing that, but I am not certain I want to sink the money into it right now. I have a new set of PS4S going on tonight, but I have been considering selling the car soon.

It looks like a stock exhaust. I would take it back to the dealer to see if they will warranty it. It shouldn't cost anything to ask.

The stock exhaust has weep holes right at the muffler inlet on both sides. Does your aftermarket exhaust have the weep holes? Those are there to mitigate this exact failure mode. On drive cycles that don't get the exhaust hot enough (ie. short trips), water will build up in the exhaust and it can rust through from the inside out.

You may get some pushback on the warranty claim. On the flip side, the Chevrolet Performance Parts exhaust (also made by Borla) also might eliminate the weep holes.. not sure on this.

Does not look like rust through - looks like crack propagated on welds (work hardening) and vibration did the rest.


Either way, sucks to see failure like that esp on like-new car.

Agreed not rust - that’s some weird shit

After looking again I would agree that the exhaust pipes look more torn than rusted. The X-pipe looks good so I don't suspect that it was caused by the Borla ATAK axle-back. I wonder if the dealership installed the replacement NPP exhaust where they twisted the pipes and put a bind on the weld. As the exhaust heated and cooled over time it could have twisted the metal?

Really doesn't look like rust. Probably a little, but rust doesn't look like that on an exhaust (I live in Quebec I know what rust is!!).

yeah those are made from 304 Stainless (we make them) that's not a manufacture issue.

I just recently noticed a big dent in my exhaust right after the cats after looking underneath listening for a weird sound. I was just about to make a thread about it and saw this. My question is did the dealership replace your dented exhaust under warranty?