misfire in cylinders 1, 2, &3, help please!

The pcm is showing codes for a misfire cndition in cylinders 1,2 &3, it also shows a code for throttle position sensor input high. I replaced the spark plugs, wires, cap and rotor but the problem is still there. I dont really notice any performance/ driveability problems, only that when its is very cold out it tends to stall if not given enough time too warm up. Does anyone have any suggestions?

How many miles do you have on it? Have you had the injectors flushed? Most of the time with a sensor saying to high of voltage it means the TPS is bad. Replace the TPS and clear the codes. See what happens misfires may go away. If not ohm the injectors while engine warm. You may have a few bad injectors. A good injector flush may solve the problem also. I do this everyday and have seen the flushes do some amazing things. Hope this helps, Dustin