Misfire at idle

[lorena]

Hi, having issues with car misfiring at idle occasionally. Idle can be a little on the rough side. Cylinder 3 is showing multiple misfires. Plugs and coils replaced on cylinder 2 and 3. New battery also added but still happening. When idle it is sitting about 625 rpm and 650 with aircon on. 2015 a3 tfsi 9200 km. Any idea would it could be before I have to go any further.

Thanks

[Steve Q]

Has the maf been considered? 

[lorena]

Mechanic was thinking maybe faulty injector, tried a fuel additive and filling from a singlewell known fuel station to eliminate bad petrol.  Car aems to drive ok , only noticed as I always turn off stop start function. It could take several mins before engine light to come on. And it doesn't happen all the time.