I have an 2009 A5 2.0 and have had massive issues with a missfire intermittently for 5 months now, had the following done
the engine management light does not always stay on. Audi could not even diagnose it as no fault code didnt come up.

Coil packs changed
Plugs and filters
Breather valve
Camshaft valve
New front exhaust box

Started it this morning and its missfiring and idling badly

The spark plugs have only just been done and the exhaust to.

Can somebody help im going insane with this car now and its cost a fortune to try to find the fault.

many thanks matthew