Cold start and hesitation

About 1 or 2 months ago I changed the spark plugs, wires, cap and fuel filter in my 92 nissan sentra. It has been running great about 30mpg until today. Today I started it up and the idle was very rough and vibrating pretty bad. I drove it for a while and it was hesitating when I would hit the gas. There was a strong sulfur smell. I stopped at the gas station and turned it off for about 5 minutes. When I turned it back on all was fine. No hesitation and had good power. Smell was gone. Any ideas.

Sulfer smell, rough idle, and throttle hesitation are all signs of your catalytic converter either out or going out. If you gas mileage starts to drop, that's another big sign. I'd get it checked. Run the crap out of it for a few minutes and then smell your exhaust. If it's bad it will smell like sulfer again a lot of the time.