[Mikery]

I drive a 1.8T a4 (or used to) its been in the garage the last 4 days.
At revs below 1500 the engine is running really badly like the timing is out. As soon as you get your foot on the gas the problem is improved.
The garage have checked nearly everything so far: plugs, coil packs, cat, dump valve, nothing comes up on the computer, the audi master technician thought it might be an air leak - its like looking for a needle in a haystack.

Any ideas?