Mysterious Throttle. 2001 PD130 sport 6speed

[FatimahDub]

Hello,

I recently had to call the AA as my immobiliser became 'activated'. The AA man plugged in his computer and fiddled around for a while, and then stripped the trim under the steering wheel and fiddled with the cables etc. Resulting in nothing he left, and suggested it might be the key. Turns out the chip was missing from the key which was fixed a day later by the VW keyman.

Upon starting my car i noticed the ASR light had come on (and is stuck on) the throttle hangs on once foot has been removed from pedal, the higher revving the more it increases. Also when the car is idling the engine splutters and judders around a lot making horrible tracker noises. Idols at 900rpm, the juddering can be stopped by very slight pressure on throttle, taking it to no more than 950rpm.

Explain someone please.

Does my pedal need replacing? Has the ECU been tampered with by accident? Any help would be appreciated.