All excellent replies.
The Torque Meter is just a warning sign of an engine problem of some kind.
I always killed the Torquemeter when teaching Engine problems in twins....forcing the use of the other engine gauges.
Once you get into a steady cruise....noting what the engine N1/Ng indications are helps in diagnosing problems with the same power setting.
Also remember engine malfunctions do not always exhibit "by the book indications during failures". Gauges sometimes go wonky although the engine is doing its thing as required.