my exhaust makes a sound when i trun off the car it sounds like a bunch of crackling noises or like if u poor water on it. friends of mine that are behind me on the road say that my car exhuast smells bad only when i floor the car.

 

I got that often, actually, when I had my stock exhaust on. When I went to an aftermarket, it never happened again. It's odd, but it may be the nature of the beast.

 

the smell is normal

 

cat fouling perhaps?