My 1995 Intrepid starts and runs fine for a couple of hours then the gauges (RPM & MPH) drop and the motor runs rough. The tranny seems OK - I can shift all the gears and get it home in this condition going 55mph.

I'll come back to the car in a few hours and it will start and run fine again - until I drive it and a few hours later it does it again.

I guess what's throwing me off is that the condition is not an always thing - just after being run for a while - any ideas? Thanks much!