What would you recommend for this Jetta?

1997 Jetta 2.0L with an automatic transmission has 99,000 miles on it. Going into reverse it is fine, but when it is switched to drive there is a delay going into gear. When going forward from a stop, you need to give it gas before it will move. Before it moves, it "bangs" going into gear. From there it is fine, except when shifting from 2nd to 3rd it "bangs" again. One time, with light throttle application, the Jetta shifted normally all the way into drive gear. Even though no "check engine" light was illuminated, there were several "knock sensor" codes stored (00577, 00578, 00579, 00580, & 00524). The codes were cleared and have not yet returned. This Jetta idles perfectly and seems to have plenty of power. Some sources have recommended "Throttle Basic Setting" procedure. We have not been able to figure out a way to do this with our Snap On Modis.