I'm sure the car is burning rich. Black smoke when the RPMs drop, fuel odor( not having a cat doesn't help to much either.) I jsut want to know if burnign rich could:
1.Can burning rich cause backfires out the exhaust( when deacclerating).

2. How much does burning rich affect performance. My car runs extremely ****ty for what it has done to it

 

Running your car too rich can cause severe damage if it is on a ridiculous scale. You can wash the rings and ultimatly destroy your engine, let alone cause big power losses. I run my car at around 13.5:1 on the air/fuel. Not too rich, not too lean. Just perfect for what my motor likes. If your car continues to dump fuel or has unburnt fuel in the pipes or muffler as a result of being overly rich, it very well could induce a backfire under decelleration.

My advice to you is: GO GET A FULL DYNO TUNE. Mail order tunes are OK, but Ive never had one spot on. Ive always gotten a mail order tune from MadZ28 and then "tweaked" it on the dyno (I prefer the dyna-pack dynos myself)

Good luck with everything.

 

Same thing is going on with my car. It has been running real rich for a while, feels slow and you definitly lose some power. I agree get a full dyno tune! Iam getting one tomorrow, can't wait!

 

Where can I find shops around my area that do full dyno tunes? I like near Pittsburgh, PA.

 

Was this a problem that just started? What kind of mods do you have done to the car? There may be a mechanical problem with your car that a tune will not solve.

 

There is a new dyno tuning shop. It has a all wheel drive dyno, nitrous oxide refilling, turbo or supercharging, fuel injection tuning, suspension parts tuning...here is the site, oh its in larksville, pa. http://speedworkz.com/

 

The car has been running rich since I got it in Dec. of 05. I fianlly have money to get it fixed. Plus, I'm hearing people say it needs to be tuned. Even if it isn't the tune, I will at least know my car is tuned good when i fix whatever the problem is.