Check all of your vacuum lines, replace them if they're more than a few years old (all of them). Check your MAP sensor as well, ontop of that make sure there's no exhaust leaks before the cat, because it can throw everything off and cause your computer to think its running lean, thus dumping more gas into the intake. Replace all of your spark plugs, plug wires, distributor, rotor, even things like changing air filters and fuel filters can help.
Basically, do a full tuneup. These are high maintenance vehicles, they like to be loved.
I drive a Cherokar.