Our 2002 Ford Escape is once again running better than when we purchased it. This bug started very intermittently; it would "race the engine" after a short trip, then return to correct idle after a few seconds. That few seconds got longer recently, and more frequent, till it happened every time we drove the car. It even happened just after passing smog check last week, and the on duty mechanic told me it was probably caused by the "IAC" Idle Air Control valve. I replaced that for $40, still had the problem. Googled the problem, then replaced the "TPS" Throttle Position Sensor; put that in for $30, still had the problem. Cleaned all associated electrical connectors to no avail. Googling the problem started getting closer to the PCM computer; big dollars. Most problems reported on the internet involved slow or dying engine for idle problems, not the fast idle I was working on. It tried to go 3,000 rpm or so unless it was in gear. I was almost resolved to taking it to the dealer, when one guy on the internet talked about measuring the resistances and voltages between the IAC and TPS and the computer itself. Luckily he said something to the effect that the readings needed to be taken at the sensor, and at the computer connector, and he mentioned a connector on the firewall. The last thing I did was to disconnect the firewall connector, which is about 60 pins and held on with a bolt, and spray it with contact cleaner. I also cleaned the battery terminals, which didn't look dirty. This of course caused the computer to reset, too. Now she idles lower than ever before; about 800 rpm where it had been 1,000 or 1100. I'm willing to bet my mileage will be improved, too. ( I spent most of two days on this bug )