Mitsubishi Repair: mitsubishi eclipse, coolant temperature sensor, engine coolant temperature sensor

Question
i have a 1996 eclipse 2.0 non turbo when the motor is cold when you start it runs ok for a minute the it starts loping then idles high after it reaches temp its ok but it shows a #4 misfire i have changed the O sensor behind the cat changed the air idle speed motor and new plugs and wires coil is ok and injectors are ok does anyone have any ideals thanks gary.

Answer
Gary,
You should check your fast idle air valve (FIAV), engine coolant temperature sensor, and your base idle setting screw (BISS) o-ring.  The FIAV is located under you throttle body and your BISS o-ring is under a cap on top of your throttle body.  Also try carefully cleaning your throttle body and EGR valve.  Replacing your PCV valve may also help.
Good luck!