p1666 Cylinder Misfire Engine Shuddering Badly - Please Help

I drove this morning to work and the car ran great no problems at all. This evening I went to drive back home and the car is shuddering like crazy and i cant drive past 30mph! No CEL but i plugged my VCDS and code p1666 shows as Cyl 1 misfiring; Im about to take the valve cover off but what am i looking for before i order an injection harness for $100++


Please help i am just trying to fix my car to drive it to work and back

Best to pull the fuel filter first and inspect for any metal particulate.

may be injector related, try data logging measuring block 13 with VCDS under a drive cycle to see what the deviations look like. Rail request vs actual during driving would help too, should be able to build up to 1700bar stable under wide open throttle.