[LeRich]

Driving my 75 1.8T auto the other day I noticed the performance had dropped off slightly. I'd filled the tank with Sainsbury's premium and was pootling home when after a few miles I opened her up as the limit went to NSL and she felt just a bit flat, as if there was no boost.

The car is running spot-on otherwise. Slightly uneven idle as normal but no misfires, drives perfectly, will happily rev if I boot it, but has lost that 'kick'. The car's in good order overall, having recently had an oil change and IMG to resolve the coolant leak so I'm puzzled.

I've had a poke around the engine bay and there are no obvious damaged or loose hoses. The turbo is quiet, the exhaust slightly louder than normal, possibly as I'm applying more throttle to overcome the apparent lack of boost. Oddly the auto box is slightly smoother, perhaps because it's dealing with less torque.

I've hooked up my cheapy bluetooth OBD reader and no fault codes (historic or pending) are being brought up. I've done a battery reset but no change.

Any ideas for what to check?