RS3 idling issue


New Member
Hi all, hoping you can help me as I'm getting nowhere with my Audi dealership in Australia trying to fix an idling issue.
Car is a 2016 PFL RS3 with 40,000km on the clock. Had it for 6 months and no issues and then had cold start issue where it would be very rough on start up and some times stall, but never during driving, I also did notice performance issue with revving occurring and not being able to put power to ground effectively. I had several limp-home modes occur as well.
Audi advised car had been tuned (which I wasn't aware of when I purchased it) so they weren't prepared to do further diagnostic work. So I managed to get the Stage 1 REVO tune removed and flashed back to Audi factory settings. As a result they were able to do several updates and replaced the PCV and said it's likely been fixed. Cold start issue improved but still rough and revving issue while driving and idling intermittently continued (hunting) and performance issue continued.

Audi then replaced fuel pump (with another RS3 that had been traded in for sale and was awaiting parts) to test if this was the problem. For the first 48 hours it almost seemed normal again but then progressively got worse again - revving issue while driving and idling intermittently (hunting) and performance issue. Car revs by itself intermittently either when cold (50 degrees oil temp or hot 95 degrees oil temp). Using a mates VCDS it has recorded multiple occurrences of P050700 - Idle Control System RPM Higher than Expected. Googling and reading what I can find on forums I haven't seen this code with the RS3.

Keen to get people's thoughts/ help on this but I'm thinking:
  • Vacuum leak / air leak in the boost - Maybe a leak - split pipe Apparently not uncommon with the PCV valve hoses as well?
  • Air intake - I note the air filter has been replaced with a non-standard one – apparently can be over oiled and clogs sensors - I note that the RS3 uses pressure sensors to work out air intake – can these be inspected / cleaned?
  • Throttle body / idle control valve
  • fuel injectors / stuck injector
  • speed sensor faulty
  • Crank sensor faulty
  • Faulty ECM
  • N205 Cam Valve / Camshaft Adjustment Solenoid