I have a 00 EM1 with intake/exhaust. The inside of my exhaust is straight black. I put it on brand new and in less than 3 days it was pure black. I have always known my car is running a little rich and as I understand thats just how they run on the stock ecu. Today my friend wanted to hear my exhaust and he notices black matter coming out. Not black smoke but like black dust it stuck all over his hand. I have tuned obd0 with wideband/RTP with BRE. Im going to convert to obd1 and probably run neptune. Im still trying to play with it. But first I have to get a p28 or p30 and a harness. So will tuning it help to not create carbon? Also How do I get rid of the carbon thats already there?

 

Carbon is formed when you burn something right? It is normal.

Water is a product of combustion also so combine the two and you have wet carbon splatting.