What else could be wrong with p0343 in a vw beetle?

we have just replace the timing belt and the sensor. what else could be wrong? its a 2002 vw beetle 2.0 auto.What else could be wrong with p0343 in a vw beetle?The fuel injection timing has to be set; and joe backyarder does not have that kind of equipment(because of the cost)....meaning it has to be taken in to the dealership.

Before on the old beetles it was gear to gear so nothing got replaced. So the timng was never out.

Now when you change the stretched timing belt with a new one, timing changes as to when the valves open and close.....as well as when ignition happens.