I have just bought this Q45

I have just bought this Q45. It runs great on the fwy. However, acceleration from a start is not smooth. I have a smell of fuel or exhaust from the manifold area. I have a scanner and pulled 3 engine codes.

Here's the codes:

1. P0306 - Cylinder 6 Misfire Detected ( could it be a coil or fouled plug? )

2. P0330 - Sensor 2 Ckt Malfunction Bank 2 ( what should I do? Replace the knock sensor? What is the term "Ckt"? )

3. P0505 - Idle Control System Malfunction ( Should I inspect and clean the throttle body with a spray? )

Thanks in advance.