I'm getting a bit of black smoke from the exhaust at revs above 5k. I've got a markD chip, magnaflow exhaust, and reletively new plugs. Any ideas? It isn't burning oil because the smoke isn't blue and it doesn't have the smell of burnt oil. Also, the car used to have a 'stage 2' ebay chip that ran extremely rich, and the chip switch helped a lot. The plugs were swapped after the new chip. Is there a possibility that running that rich for so long tasted the O2 sensor? I don't want to spend $85 on something I don't need. I think it was replaced with the cat about 3 years ago.
Topic: running rich (Read 1989 times)