So I have no clue about the engine or what this could possibly be but: When I am hard on the gas for a little while or have just been driving for a while I smell this horrible sulfur or rotten eggs smell coming from my car. I could be at a red light with my foot on the brake or just getting out of my car after driving for a while and it definetly is coming from the car. Its seems to be coming from both sides so sometimes passengers mention it to me. You can never smell it in the car unless the windows are open. What could this possibly be?