it appears by my reading of other post the p 1582 code is very common in the jetta...well let me say it is in the 98 bug also, think i will try the throttle body cleaning, I have code p 0422 showing..any suggestions on this one. I have liked VW's sice my teen years, I learn to drive on a 65 bug that I still own 30+ yrs later. But this 98 is about to turn me away, it has 146k on it but has these crazy issues
Yes, throttle body cleaning is a good first place to start.
Cleaning helps on vehicles where the idle is too low.
If the idle sticks high after cleaning & throttle adaptation (with appropriate scan tool), then a "capacitive discharge" may need to be done, to clear the ECM "learned" idle setting.
A capacitive discharge is removing the battery cable clamps from the battery and then touching the cable clamps together (just the clamps) for a few seconds. This drains any stored learned ECM values.
On vehicles that still have a throttle cable such as yours, make sure that the throttle cable is not adjusted too tight, as this can also cause a high idle condition... since the cable will not allow the throttle to sit closed all the way.
The cat code is most likely a bad cat if it is still original. Any rattling from the cat if you knock against it with your fist (while the cat is cold)?