stumbling

hi every one, i have a 92 Z/28, TPI 350, ILL be driving and it will stumble, loss of power, service light will come on, and sometimes the car dies. After driving a bit, the light goes out, and a bad gas fume smell runs through the passenger area. And power comes back. when i test for codes once im home, no codes,,,err.
I've checked the TPI sensor, changed the O2 sensor, and i still have the problem. It's intermitant, and i never know when it will happen, can any one help please!! thank you mark w :banghead:

Sounds like you need a scanner hooked up so you can see what is happening when it acts up.