02 GP lunges while at a stop

Sometimes, when coming to a stop, feels like the brakes are working hard to slow down the car and the trans isnt downshifting properly. At normal idle car is around 800 rpm, sometimes rpm is at 1200 and you need to press the brake good to keep from hitting the guy in front of you. Is this a tranny issue or is throttle sticking?

1200 is way to high. could be a vacuum leak or a bad TPS. IS the check engine light on, if so get it scanned and report back with the DTC's

No engine light on and no codes. Doesn't happen all the time, maybe 50% of the stops at a stop sign/traffic light. No misses, no stalls. Someone wouldnt even notice when driving it unless they were told about the issue.

I would check the throttle body for carbon deposits. Sounds like occasionally the throttle is hanging slightly open causing the high idle and pulling through the brakes.

Could also be your IAC Idle Air control valve. It is next to the TPS and cleaning it out may help. At times lots of "gunk" gets on the plunger and it sticks.

Cleaned mine out last month, and it was VERY dirty. Use Brake Cleaner, Throttle body cleaner, or electrical contact cleaner. Ensure O-ring is a tight fit also.