I have done several searches and have still not come up with an answer to what my problem is.
I have a 97 SE that will idle well most of the time (cold or warm), but occationally sputters down to about 500 RPM, then catches and goes up to about 2000 RPM. From there it goes back and forth and does not idle well, almost stalling out. I have already replaced the plugs, wires, distributer cap, rotor and air filter. I then removed the throttle body and IAC valve and cleaned them well, including the connections to the IAC and TPS, both of which received some dielectric grease. After putting on a new throttle body gasket and reinstalling everything my Jeep runs worse. Now it sputters most of the time at idle. The only code that it is showing is a 21 which I believe has to do with one of the O2 sensors.
My question is, what part should I start with? The IAC or TPS?
Your help will be greatly appreciated.