HAVE THIS 99 JETTA, INSTALLED NEW THROTTLE BODY AND PERFORMED THE BASIC RELEARN FOR IDLE. NOW IT IDLES GOOD IN PARK & NEUTRAL BUT WHEN PUT INTO GEAR IT JUMPS UP TO 1,000RPM. IF YOU SIT FOR A WHILE IN GEAR IT FINALLY FALLS BACK DOWN TO 750-800RPMS. AFTER DRIVIN... Login to read more.