My 2006 A6 (3.2) has developed a multi cylinder missfire and ESP warning when I accelerate quickly. It sometimes clears itself, and other times an engine off/engine on clears the problem.

I was trying to fault find at the weekend and removed the small pipes from a sensor (Pierburg PA6 GF30) behind the cyclinder block (attached picture). Took the car for a spin, and it managed to rev a lot higher without the fault forming every time, but still happenend.

A quick Google search revealed that it is a vacuum boost sensor, however, further research claimed that the MAP sensor could be faulty, which sits behind this.

Would anyone have any insights into this problem, if common, as trying to book the car into Audi (in Hong Kong) is a pain, with very long lead times, and thus, trying to self fix.