Nissan Repair: 2000 Nissan Xterra, nissan xterra, spark plug wire

Question
I am pulling two codes off of this vehicle with 82K miles.  One is P0302 which I understand is Cylinder 2 misfire.  The other is P0325 which is Knock Sensor Bank 1 (Sensor 1).  Okay, so what should I be checking to find the root cause of the problem?  Vehicle does run rough under mild acceleration & check engine light flashes on and off with the more severe occurrences though it doesn't stay on.  I figure it is a faulty injector or bad spark plug/wire to that hole but I really don't know.

Thank you for your time.

Andy

Answer
Andrew,

First, replace the knock sensor and do a tuneup to replace the plugs, wires, cap and rotor.  It might be an injector.  To check for this check the fuel pressure and a leakdown check after the ignition is off.  If the pressure bleeds off rapidly you have a leaky injector.  Number 2 might have a really black plug and that would mean over rich.  CHeck this out and email me back.