black smoke

[rudy herrera]

i have a 1990 mustang it has a intake and flowmasters that are dumped with no cats recently i notice that the car smells alot like gas and yesterday when i was at open trottle i notice alot offf black smoke wat could it beeee thanks

 

[90stang5speed]

Black smoke is usually a rich fuel mix. Do you have an air/fuel ratio gauge? WOT AFR is usually 12.4-12.8 on NA cars. maybe Fuel pressure could be too high or maybe a failing O2 sensor or an exhaust leak before the O2 sensors could be sucking fresh air in during idle & cruise. that could throw off WOT fuel trims a bit causing a rich mix.