2002 Mercury Grand Marquis Q&A

2002 Mercury Grand Marquis Question: P0304 Cylinder 4 misfire / head gasket issue?

4.6L v8 with mil light on code is P0304 Cylinder 4 misfire. Coolant overflow was light brownish in color. Could this be a blown head gasket? If so , what is a ballpark estimate to have this repaired -
Answer 1
Common Problems that Trigger the P0304: Worn out Spark Plugs Ignition Wires, Coil(s), Distributor Cap and Rotor (when applicable) Incorrect Ignition Timing Vacuum Leak(s) Low or Weak Fuel Pressure Improperly functioning EGR System Defective Mass Air Flow Sensor Defective Crankshaft and/or Camshaft Sensor Defective Throttle Position Sensor Mechanical Engine Problems i.e Low Compression, Leaking Head Gasket(s) or Valve Problems are you looking to do both gaskets or only one side? -
Comment 1
I Have P0307 cyl 7 misfire, runs rough no smoke coolant clean but how do I find out which of these problems it really is without being at the mercy of the repair shop to be honest. -