[SRG]

Well, you haven't given us a lot to go on, but let's see,

-old, dirty spark plugs? (how many miles?)
-bad gas? (try some dry gas/stp fuel system cleaner)
-old spark plug wires
-clogged fuel injectors?
-dirty air filter?

I don't think the freon level effects how well the car runs, if the level gets too low, the pressure switch won't let the compressor run.

just guessing here....

srg