...cleaning my airmeter...
Yep, didn't think it would make any difference, but I tried it and it is a lot livelier...
All I did was take my airmeter out of my 100 000 mile E46 330ci, spray car cleaner (lots of it) trough the plastic grid at the hot wire, put it back together and took it for a test drive...
The carb cleaner was bought off EBay for a few UKP.
Worth doing!