I've been trying to trace down the cause for a while now, and it wouldn't be that big of a deal if I weren't getting at least 1.9* of KR whenever accelerating. At Idle, if I give it gas I will get a vibration in the 1100-1200 RPM range and the scanner will occasionally show some misfires mostly in cylinder 4. I've changed the plugs, wires, fuel injectors, and sprayed for vacuum leaks without any success. I am running a stock pulley, and have no engine codes.