Off topic: Misses when AC is on

[Ryan]

Off topic cause it's on my 2000 Mercury Cougar 4 banger. When the ac is on and going up his, the car hesitates like it's missing.

 

[Killa-Cotton]

Sounds like the strain on the motor is causing it to miss. I'd try a good tune first. Fuel filter second. AC can put alot of stress on a 4 cyl.