I noticed my MK1 TT BAM’s Turbo was not spooling as linearly as it normally did so I took the advice of my local mechanic and disconnected the battery, left it for 5 minutes and reconnected it with a view to resetting the throttle response, etc. It made a HUGE difference, I can now feel the Turbo engaging lower down in the rev range and can hear the wastegate working as it used to. I’m an aircraft engineer so I’m not mechanically ignorant so here’s my question....why is the performance of the car degrading back to a point after a few hundred miles until my next visit to disconnect/reconnect the battery? Is it an ECU issue? The car runs perfectly except for this performance hiccup 😀

Any help would be very appreciated!