Car revving itself

Hi I have 2010 (60 plate) a3 1.6 petrol engine and have been having a few problems with it.
Every now and then when I turn it on it revs itself just up to 1.5 revs and when I move off it has a delay in power and when I put my foot down it delays 2 seconds then opens up.
After 2 minutes it stops and then the esc light comes on. If I turn the car on and off the light goes off and it doesn’t rev itself.
Been to several garages and when the engine light came on the mechanic said he’d never seen the code before.
Since the issue has started I’ve driven 15 hours on the motorway in 2 weeks and it has been driving like normal.
Any ideas on what the issue could be ?
Thanks

No neither were VAG specialists, I cannot remember the code from the first gageâtes but the engine light turned off and the drive couldn’t find a problem.

Engine light only came on once and turned itself off but code was explored could have been 1 or 2 things but the Audis don’t have whatever it was (can’t remember)
Thst was checked and it was functioning normally