Ok, here goes,

I decided to clean out the throttle body since it was very oiled up.

I removed the airbox, unclipped the multiway plug and removed the four allen screws retaining the throttle body.

I then thoroughly cleaned the body using carb cleaner and a soft cloth until it was nice and shiny.

I wiped out the plenum and wiped clean the pitot tube then reassembled everything.

When I re-started the car the EPC light came on followed by the CEL and the car ticked over quickly and wouldn't respond to any throttle pedal.

I connected my laptop using VAG-COM 409.1US and checked for fault codes, there were none. I reset codes anyway and the CEL went out.

The EPC light remains though and the car ticks over poorly, with the engine pulsing up and down between 800 and 1200 RPM. I have re-checked my work and nothing is out of place.

I'm flummoxed, I can only thing that I dislodged some oily debris into the pitot tube and have fouled the sensor there.

Any ideas chaps?

Throttle body adaptation?

Please elaborate, the car is intermittently un-driveable and I don't know what to do about it.

As you have removed the plug on the throttle body you now need to run a throttle body adaptation. As you have VAG-COM working already you're half-way there, just need to follow these instructions http://wiki.ross-tech.com/wiki/index.php/Throttle_Body_Alignment_%28TBA%29#Drive-by-Wire_.28DBW.29_Engines_using_KW-1281

Brilliant, worked like a charm.

Hats off to you guys, you know your stuff.

Just the drivers door lock barrel and the console bushes left to do now.

Thanks again.