The throttle plate is the big gold plate inside the throttle body. if you loosen the band on the filter arm and pull it off, you'll see it in there. Just spray some cleaner in there. But, that's just one possibility. Still check for leaks, and clean the IACV. It may be stuck, and the ecm is cutting fuel to keep it in check.

 

Any pulsing idle is definitely a sticking IAC valve.

The best way to clean it is to remove the IAC motor from the valve. This will require a 5 point torx called a pentacle bit. They are very hard to find.

with the motor removed, the shaft can be spun 360 degrees and tested by hand for snags.

Theres a little rotary shaft that spins on mini bearings. if you remvoe the motor from the valve, you can feel the hang ups in the shaft.

clean it out, then a little thin oil on the bearing ends.

Idle will be super stable.