2005 ford taurus ruff start

My 2005 taurus is starting ruff and there is a slight gas smell. I took it to the shop and they ran a full diagnostic on it and said there was no problems. The check engine light is on. It has a new alternator and battery. Does anyone have any ideas of the problem?

Sounds like you have a misfire, and since you mention you get a smell of fuel, it's probably an ignition system misfire. When is the last time the car had a tune up consisting of at least spark plugs and plug wires (if not Coil on Plug)?

If the Check Engine Light is on or even has been recently, there will be diagnostic codes stored in the system which should further indicate what system you should be looking at. My bet is you'll have a P030x code where 'x' will be a number indicating which cylinder is misfiring.

-Rod