2002 Mitsubishi Galant rough idling

My car makes this rough idling only at drive. Park neutral and reverse its ok its shaking but not as bad at drive. Then sometimes when I start idling is rough and it dies, and I smell gas. A month ago my car just stop, so bring it to a mechanic, he said crankshaft sensor bad, since timing belt is almost due for replacement he did replace both, he told me timming is alittle bit of so he said he ajusted it. When I got the car driving home it dies on me. Start it bring it back he ajust the idle. My car never dies before till he replace the sensor and belt and adjust the timming. Just what you to know history of my car. Ty