159 Cruiser and
AO Silver Member
Join Date: Jul 2012
Location: United Kingdom
Try switching the aircon off (see if that changes it), the compressor switches on and off, and changes the demand on the engine. If you have just got in the car it will be trying harder to adjust the temperature, it switches on and off to reduce fuel consumption when not needed.
if it is doing a regen, a quick look at the turbo boost dial should tell you, if it drops like a stone when you take the foot off the accelerator, it is doing a regen.