Originally Posted by CantComplain

If you haven't inspected and/or cleaned the throttle body yet, that would be my next step. See https://www.youtube.com/watch?v=1cX0pCJbapk or any number of other TB cleaning vides, I just happen to like this guy. This particular video doesn't go into great detail on the actual cleaning but once you're staring down the barrel of it, gently open the "butterfly" and use a solvent (such as throttle body cleaner) to clean the plate on both sides, the edge/circumference of the plate, and the barrel where the plate closes on it. You can get down the barrel too, but just don't scratch it with a tool--use a clean rag or paper towels. If it's chunky, that's a good indicator it's letting in extra air and could be causing your issues. Take your time, use a toothbrush, wipe it all out.

If you go slow, it will take an hour and cost $10 if you use name brand TB cleaner. And it's well worth it even if it doesn't solve your problem.