ECU Remap and resets
 

This is for those knowledgeable in mapping.

Scenario had an engine warning which has now gone but it appears that the map has reverted to a previous map (e.g. last but one map). Is that possible.

What makes me know that is the previous map had a certain boost level at certain revs e.g. 1.35 the new map increased the boost, etc.

Can this happen (well obviously it appears to be) or does the ECU take a while to get back to its previous state (its been 2 days now and 150+ miles)

it is possible that your ecu has defaulted to the safety of the limp home map where it reduces power. My car is currently running on this very map, it is a pain in the ar5e but should save your car from any nastyness. You can reset the ecu by disconnecting the battery for a while and see if this makes any difference.

Its not limp as such (e.g. where it won't rev beyond 6k, low boost in low gears, etc) it's fine in that respect.