I have a 2002 F-150, 4.2 V6. It has erratic idle when stopping at lights and stop signs. I have replaced )2 sensors, IAC, TPS, plugs and wires and cannot rectify the problem.
replaced IAC, TPS, plugs/ wires and coil pack. Truck still suffers from erratic
idle. Also replaced all 4 02 sensors.
Sound like you need to check all your vacume hose,s and your intake gasket for leaks,
Especially the PCV valve and elbow, the elbow connecting the PCV valve the the underside of the throttle body often become badly deteriorated and cause a vacuum leak with symptoms like yours.
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