The TPS doesn't seem to hard fail but just exhibits transient problems with starting or running.
You mention the G56 ECU - is it their map in an unlocked S&S or the Emerald?
For info, the S&S ECU starts the engine on a fixed map then switches to the (normally) closed loop main map as it warms up. This changeover happens pretty quickly within maybe 15 -30 seconds or so.
If you are having to crack the throttle to maintain cold idle then it could be the TPS just needs a very small tweak to it's alignment.
