im new to this site and need some advice. i have a 99 mustang v6 with a 5 spd. It will drop to 500 rpms sometimes as i come to a stop and it will surge. At wide open throttle as i merge onto the highway for about 30 seconds ill let off the gas and go back into it and i will have no power in the pedal than after about 4 seconds of that i regain power! it also has a sulfer smell when i try to give it gas. no check engine lights. it actually died on me once as i came to a stop.