Brand new audi owner here!

Check engine came on after an oil change, code PO305. Thumping from idling and some acceleration

Replaces piston 5 ignition coil and spark plug and cleared code...but still having the same symptoms but it doesnt seem as bad

Also there seems to be a slight burning smell..dont know if its related or not

Check engine light has not come back on after about 20-30 miles of driving. It did blink at one point but then stopped

Im thinking ICM replacement is the next step...but where is it and which one controls piston 5?

Any advice or knowledge is greatly appreciated!!

Ok check engine back on, havent checked the code to see if its the same one