I’ve got a VW Golf 2016 1.8t with a M/T. A while back I got my first misfires and they were very sporadic and I thought it was bc of the cold winter we had this year in NJ. Car slept outside all the time. I attempted to fix by doing typical tests like checking Sparks, coils, and spraying for vacuum leaks. Did visual inspection and got nothing. After messing with sparks and coils the misfires worsened.
I swapped the EVAP and PCV for general maintenance bc these tend to go bad at 60K
Also installed new Spark plugs and checked coils for spark and they were fine.
Took it to a shop and they found severe carbon buildup so I had the car walnut blasted. It currently runs better but still has misfires. Almost like it did before I messed with the plugs and coils. The car does get better and symptoms disappear when I take it for a drive on a highway and I’ve got the rpm’s slightly over 2000. When the car is at lower speeds for a while and light throttle it struggles and occasionally jerks.
Wondering if it could be a vacuum leak or fuel issue.