2000 jetta w/ code 1582

:banghead:We just picked up a 2000 Jetta GLS with the 2.0 and 5 speed. I am fighting with a code 1582 for the idle adjustment at the limit. We have been working on an initial round of maintenance items for the engine, hoping that we would stumble on to the answer, but no luck yet. So far we have done the oil/filter, spark plugs, and engine air filter. Obviously unrelated, we have also changed the cabin air filter.

I have read strings suggesting cleaning of throttle body, mass air flow sensor, catalytic converter...

Any thoughts on the best plan of attack and order of likelihood would be appreciated.