I suggest the Ease scanner because they are a tier 2 suppler to GM so their scanner was designed with GM engineering input and information that is not known by the public for their enhanced PIDs plus how the VPW functions.

If interested you can purchase it via our frontstore and this is the model you would want :

Ease GM Enhanced OBD-II

Your autotap does less then about 10 frames a second where with Ease you get 40 F/ps.

In your case PCM cycles are then missed where with the Ease your getting far more data cycles.
Also the Ease supports all GM PIDs, has bi-directional, full EPA IM snog tests and O2 tests.