Well when the engine light came on, I was just driving gently to the shops for lunch, probably no more than 45mph. Nothing happened, I just happened to notice the light was on, so I checked it with VAG-COM and only got the two air injection faults. Thought nothing of it at the time, no running problems or anything, so cleared the DTCs and everything has been fine.

Drove home that night, no problems. Headed north on friday, no problems again. Drove for about 110 miles this morning, no problems at all then suddenly this loss of power. I was in cruise control, 75mph.

The only thing I can think is that the fault caused a hiccup in power which triggered the ABS which perhaps misread the throttle position due to it being in cruise? Dunno, scratching my head, but this is the fault read out from this morning and the engine had not been switched off since the fault occurred:-

Engine:

17831 - Secondary Air Injection System; Bank 1: Insufficient Flow P1423...

18047 - Accelerator Position Sensor 1/2 (G79/G185): Implausible Signal Readiness: 0010 1101

ABS Brakes:

18264 - Throttle Potentiometer (G69): Error Message from ECU P1856 - 35-00

I'm pretty sure this is connected to the very intermittent problem that occurs at about 3500 to 4000rpm under load when there's a slight hiccup, almost like it's thinking of changing down a gear or something. I've been driving it like a grandma for a few weeks now, frightened something else expensive is gonna break on this gearbox, but now I'm starting to think the real problem is revealing itself.

Once these problems are ironed out and it's had a bit of TLC on a few scratches and chips, I think I'll be parting with it anyway as I (and my wallet) have had quite enough of 8 ownership