Some CELS can be weird. Usually I turn the key on the on position to prime my pump. But i was in a bit rush after work and just turned the car on. It was around freezing, drove a block or so and the CEL came on. Had the same code as you. Reset the the code, and pulled the cyl 4 plug and everything looked good. So did the wire. Put about 250 miles or so on it since, no code has popped up.
As for wires, I think all are good. I had great luck with cheap autozone wires on my silver s3 car. lifetime replacement too.
never cared for granatelli. i remember when their wires first came out on mpx site. received them and they would not click onto my plug! mpx went through this big spill saying it was because i was running "shorter ngk 4306 plugs and the wires were designed for oem champion plugs." i had to return them and eat the shipping cost. I am sure they fixed that issue by now with their wire design since the ngk 4306 is like the best plug for our cars.
I am currently running taylor 8mm wires. Local company and , american made.