Cincy7

When I jump on it I get a cloud of Black smoke. If I am running rich, what do I change? I get good gas mileage. Average 17 in the city and 25 on the highway. I'm replacing the main cat this weekend.

adamlewis

If you see black smoke its one of two things. Carbon or Gas. Both of these can be good OR bad. If its a lot of carbon, you dont want that going through your turbos...but you DO want it out of your engine. If its gas you could be running too rich which CAN cause predetonation...but you want to run rich under WOT to protect the engine.

How much smoke is it? If you stand behind your car at idle, do your eyes start to burn? If they do, dont feel bad Most tuned ones are like that. Most tuned FD's Ive seen look like shitboxes to the average Joe because of all the smoke they blow.

Exactly how much smoke are you blowing? Does it pour out? Or does it just kinda come out under WOT?

adamlewis

Oh...Forgot to add; If you are running rich and the smoke isnt that bad, DONT mess with it. Youre just protecting your engine.

Cincy7

Don't know if it gas or carbon. What I do know is the outlet of my catback is coated with soot. The black cloud only appears on hard acceleration. Also, a get backfiring when I come off the accelerator.