i own a 96 rs and ever since i changed my exhaust and cat convertor it sounds like its coughing.. i guess you could say its back-firing. ive changed the oil and it didnt help.. apprently im blowin a little black smoke out the back.. any guidance would be great.

 

what color is the smoke?

 

black

 

possibly a bad o2 sensor or it's misfiring. that's just my thoughts.

 

I would call it more of a popping noise then backfiring. Got any CEL's?

 

did you get a freer flowing exhaust? im thinking its just the popping noise that you get from opening it up.