That is the ISC trying to get rpm down.
Does this happen immediately when you start the car?
Engine warm or cold?
Disconnect the vacuum line at the manifold, the one that feeds accessories,
plug that port. Does it still happen.
Terms keep changing.. they IAC, IdleAirByPass (IABP) ISC, (except Air
Charge Temperature Sensor - which is part of the MAF)
all do the same function.
Look for the vacuum leaks, like I said, also check for intact PCV Valve
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