02 with 85,000 miles > if you haven't service/clean the throttle body assembly then you might want to start there. After I've cleaned mine it really made a world difference in RPM stability and responsiveness. The gunk I took out of that thing lollll Was quite embarrassing in fact
Possibly unrelated I understand but this is where I'd start with that sort of mileage and RPM issues (if you haven't done it). Few DIY articles around on the Pelican Parts website I'm sure, procedure takes about 2~3hrs max. doesn't hurt!
Carb Cleaner aerosols/can/sprays; wear a mask and glove if you use
