Why is my '98 Ford windstar is running rough after a tune up?

I changed out the plugs and wires and it ran good for a day or two but has a lot of hesitation at lower rpms but if I speed up it goes away. Also have a gas smell in my air conditioning when I'm stopped but not while driving. Can anyone help? I'm tired of putting money in this thing.

It could be your coil pack I had the same problem and I replaced the coil pack it ran perfect.

Did you change your air filter fuel filter

Could a bad pad or wrong plug man or wires