2002 Mercury Cougar

Engine Mechanical problem
2002 Mercury Cougar 6 cyl Front Wheel Drive Manual 61000 miles

My check engine light has been going on and off for a while now, and then my car started to hitch. I had a diagnostic done on my car and ended up having the EGR valve replaced. It didn't help at all. Basically I'm noticing that the " hitching" occurs only when I'm holding the gas at a consitent pressure. Holding a steady speed and not doing an on/off the gas pedal deal. It feels like my engine just wants to give up, like it's not quite getting gas, and it's going to stall out. I hear no noises from the engine when the hitching occurs, and my RPM needle isn't effected either. Thank you for your time!
April 14, 2008.

I am having the exact same problem with my 2001 mercury cougar. 6 cylinder, automatic- slight hesitation at 37 mph then at 47 mph. It also is getting bad gas mileage since this started. Have you came up with a fix?