"Idle adaptation at limit" replace throttle body?

I don't know if it's the same unit as the MKIII (96 Jetta), but I bought one from BBA manufacturing in Taunton, MA. Cost was $140, including shipping. They included a label to return the core.

Mine threw another P1582 right after I passed the emissions. I called them and the shipped another. The check engine light went away a week later. I shipped the replacement back to them.

Does it have the throttle position sensor as a part of the unit. If so, you can try cleaning it. DO NOT USE THROTTLE BODY CLEANER TO CLEAN INSIDE THE TPS. I don't care what anyone says about the cleaner being safe for sensors. I melted mine with that junk. Go to radio shack and get contact cleaner. Clean the 'tracks' where contact comes in contact.

The rebuilt unit I bought came with these instructions to reset the ECU:

"Warm the engine up. Disconnect the battery for 10 minutes. Re-connect the battery. Switch on the ignition for 15 seconds without starting the engine. Then start the engine and leave it ticking over without using the throttle for 5 minutes. T%est drive it using various throttle openings for 15 minutes"

I thought this was a good way to do the throttle body alignment

"For this all you have to do is unplug the battery for about 5-15 minutes. When you replug it, turn the ignition to the ON position WITHOUT starting the car. You'll hear some funky noises, that's the throttle body alignment which is doing itself."

Don't replace it yet! Clean it again! The new one will eventually get dirty and throw the same fault code. No need to go throwing away your money on a new throttle body. I've been dealing with p1582 fault codes ona mk4 style volkswagens for years, and only recall replacing a hand full of them. The only time I suggest a throttle body be replaced is if there are errors during the adaptation process that lead to out-of-spec electrical values on the unit itself when further tests are performed.

I recommend reaching under the wiper cowl and disconnecting the ecu for at least 10 minutes after everything is said and done. It is important that you have the throttle adaptation reset. Reason being that the throttle body is synchronized to the ecm electronically. This matching process allows the ecm to memorize the closed throttle, wide open throttle and pre-start throttle positions. You cannot just plug it in and expect your car to be on its best behavior when the computer has already memorized the values of the dirty restricted unit. Don't have vag-com? Take it to someone who does or have a volkswagen specialty shop reset for you for what usually is a minimal charge.