Ash flakes coming from exhaust
 

This was something I noticed today upon starting the Z. These black flakes were coming out of the exhaust, mostly driver side. They are waxy on one side and matte on the other. I don't have cats, so wouldn't be from them. I'm thinking maybe some kind of resonator packing? My car has the Corsa catback setup. Car sounds normal, no lights popping up indicating a problem.

Has anybody seen anything like this? The one in the pictures is on the extreme large size from what I saw, most are very small.

https://www.zr1.net/forum/attachment...1&d=1725158784

https://www.zr1.net/forum/attachment...1&d=1725158784

https://www.zr1.net/forum/attachment...1&d=1725158784

Re: Ash flakes coming from exhaust
 

While I never saw this on my catless '95 or my catted '93, perhaps it could be just from carbon buildup that is finally flaking off. While not really related, I know that on the inside top of my Weber grill, it gets a buildup that looks like peeling paint, but the owners manual says it is just carbon and grease build up from cooking, so I use a wire brush to scrape it off. Would not surprise me that this might be possible in an exhaust system, especially if the car occasionally runs a bit rich. Just a thought. --Bob

Re: Ash flakes coming from exhaust
 

Marc gave me a similar response, so that is probably not a bad assumption. He also informed me there is no packing in the Corsa resonators or mufflers, so its not that.

The car used to run very rich at WOT (below 10 AFR), but I dialed back the tune a while back. Perhaps this is just the build up finally coming out.

Re: Ash flakes coming from exhaust
 

Yeah looks like carbon flakes. Run some WOT on highway or somewhere when you can keep the pedal on the floor for some decent long pulls and you will clean more out.