can't figure out why the engine still revs even after i put in the clutch.

[sokaplaya21]

I just purchased a 2000 mercury cougar about 8 months back in south carolina. I moved to New Hampshire (much colder) about 4 months ago. I didn't have this problem when i was in south carolina. However since about a month and a half ago, everytime i push in the clutch to change gears the rpms go up. i just changed all of my O2 sensors, i took out the performance chip i had in the car, gave it a tune up (new spark plugs, new fuel filter, new wires), and a new starter.

also the radiator light is on and i can't figure out why. i replaced the reservoir cap because this car doesn't have a radiator cap.

The ABS light is on,and again i don't no why. I no the previous owner put on after market racing brakes, pads, and rotors.

[MagicRat]

I wonder if you have icing inside the throttle body, which is preventing the throttle blade from closing fully when you release the gas pedal during an extended drive.

The cooler, damper NH weather is partly responsible. Also the radiator problem may be related, if there is a problem that allows the engine to run too cool.

Finally, if the previous owner modded the car, he may have installed a "cold air intake" system which might be contributing to the problem. Ask him or her if he did this and if so, does he have the stock one lying around. If yes, get it and put it back on.