All this shaking and rough idling...help!
 

Hi I have a 2013 A4, it started idling and shaking hard when I’m in traffic moving slowly or reverse parking, also idles when I started the car sometimes, it even idles like it’d almost stall when I drive around 30 km/h or so, it did stall once completely when I took my foot of brake and started to move at traffic, however, there is no code shows up but did find oil in one of of spark plugs. I really did not want to spend thousands to fix something i could’ve done it cheaper. Any suggestions is very appreciated! Thanks so much!