• Register Today It's free! This box and some ads will disappear once registered!

Misfire P0304


ZO6_Vette

Member
Joined
December 13, 2008
Messages
68
Reaction score
0
City, State
Long Island
Year, Model & Trim Level
2006 EB
Hi,
Looking for some opinions on where to go from here.
2006 Explorer 4.0 43,000 miles throwing P0304 code.
It seems that that the fault only happens a very short time after start up.
If I clear the code it will not happen again until the car sits for a while and restarted.

Did a compression test on cylinders 4 and 5 and they were identical at 155.

I have replaced the coil, wires and plugs, sprayed around the intake manifold and found no leaks.

I did a power balance test using my Autoenginuity scanner and it showed all cylinders were fine.

Below is the freeze frame data for 3 instances of the fault notice the run time.



Vehicle Manufacturer: Ford
Vehicle Calibration ID: PWFG0AB.HEX

1)..................................
Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 87.843 %
Engine Coolant Temperature = 172.4 °F
Fuel Trim Bank 1 Short Term = 0.781 %
Fuel Trim Bank 1 Long Term = 2.344 %
Fuel Trim Bank 2 Short Term = -2.344 %
Fuel Trim Bank 2 Long Term = 1.562 %
Intake Manifold Pressure = 12.473 psi
Engine RPM = 2,324 rpm
Speed (OBD) = 27.34 mph
Timing Advance = 18.5 °
Intake Air Temperature = 86 °F
Mass Air Flow Rate = 483.85 cfm
Throttle Position(Manifold) = 30.98 %
Fuel trim bank 1 sensor 1 = 0 %
Fuel trim bank 2 sensor 1 = 0.781 %
Run time since engine start = 64 s
Fuel Rail Pressure (relative to manifold vacuum) = 54.344 psi
EGR Commanded = 0 %
EGR Error = 0 %
Fuel Level (From Engine ECU) = 28.627 %
Distance travelled since codes cleared = 3,063.981 miles
Evap System Vapour Pressure = -51.5 Pa
Barometric pressure (from vehicle) = 14.939 psi
Catalyst Temperature (Bank 1,Sensor 1) = 1,061.24 °F
Catalyst Temperature (Bank 2,Sensor 1) = 1,061.24 °F
PID: 41 = 0
Voltage (Control Module) = 13.864 V
Engine Load(Absolute) = 62.745 %
Commanded Equivalence Ratio = 1
Relative Throttle Position = 18.431 %
Ambient air temp = 66.2 °F
Absolute Throttle Position B = 50.196 %
Accelerator PedalPosition D = 33.725 %
Accelerator PedalPosition E = 40.392 %
Accelerator PedalPosition F = 29.804 %

2)..................................
Vehicle Manufacturer: Ford
Vehicle Calibration ID: PWFG0AB.HEX

Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 63.137 %
Engine Coolant Temperature = 181.4 °F
Fuel Trim Bank 1 Short Term = 1.562 %
Fuel Trim Bank 1 Long Term = 3.125 %
Fuel Trim Bank 2 Short Term = 0 %
Fuel Trim Bank 2 Long Term = 2.344 %
Intake Manifold Pressure = 10.008 psi
Engine RPM = 2,074.5 rpm
Speed (OBD) = 11.185 mph
Timing Advance = 29 °
Intake Air Temperature = 80.6 °F
Mass Air Flow Rate = 287.727 cfm
Throttle Position(Manifold) = 23.922 %
Fuel trim bank 1 sensor 1 = 3.125 %
Fuel trim bank 2 sensor 1 = 0.781 %
Run time since engine start = 62 s
Fuel Rail Pressure (relative to manifold vacuum) = 54.423 psi
EGR Commanded = 51.765 %
EGR Error = -3.906 %
Fuel Level (From Engine ECU) = 98.039 %
Distance travelled since codes cleared = 35.418 miles
Evap System Vapour Pressure = 17 Pa
Barometric pressure (from vehicle) = 14.794 psi
Catalyst Temperature (Bank 1,Sensor 1) = 1,006.34 °F
Catalyst Temperature (Bank 2,Sensor 1) = 1,006.34 °F
PID: 41 = 0
Voltage (Control Module) = 13.966 V
Engine Load(Absolute) = 43.529 %
Commanded Equivalence Ratio = 1
Relative Throttle Position = 10.98 %
Ambient air temp = 60.8 °F
Absolute Throttle Position B = 35.294 %
Accelerator PedalPosition D = 28.627 %
Accelerator PedalPosition E = 36.471 %
Accelerator PedalPosition F = 25.49 %

3)................................................
Vehicle Manufacturer: Ford
Vehicle Calibration ID: PWFG0AB.HEX

Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 21.961 %
Engine Coolant Temperature = 170.6 °F
Fuel Trim Bank 1 Short Term = 3.125 %
Fuel Trim Bank 1 Long Term = 7.031 %
Fuel Trim Bank 2 Short Term = -0.781 %
Fuel Trim Bank 2 Long Term = 3.125 %
Intake Manifold Pressure = 4.496 psi
Engine RPM = 704.25 rpm
Speed (OBD) = 0 mph
Timing Advance = 27.5 °
Intake Air Temperature = 100.4 °F
Mass Air Flow Rate = 32.406 cfm
Throttle Position(Manifold) = 14.51 %
Fuel trim bank 1 sensor 1 = 3.125 %
Fuel trim bank 2 sensor 1 = -0.781 %
Run time since engine start = 84 s
Fuel Rail Pressure (relative to manifold vacuum) = 56.202 psi
EGR Commanded = 0 %
EGR Error = 0 %
Fuel Level (From Engine ECU) = 83.137 %
Distance travelled since codes cleared = 19.263 miles
Evap System Vapour Pressure = -86 Pa
Barometric pressure (from vehicle) = 14.794 psi
Catalyst Temperature (Bank 1,Sensor 1) = 629.42 °F
Catalyst Temperature (Bank 2,Sensor 1) = 629.42 °F
PID: 41 = 0
Voltage (Control Module) = 13.889 V
Engine Load(Absolute) = 15.294 %
Commanded Equivalence Ratio = 1
Relative Throttle Position = 1.961 %
Ambient air temp = 59 °F
Absolute Throttle Position B = 16.863 %
Accelerator PedalPosition D = 18.824 %
Accelerator PedalPosition E = 29.02 %
Accelerator PedalPosition F = 18.431 %
 




Chikar

Active Member
Joined
November 26, 2010
Messages
192
Reaction score
0
City, State
Ladysmith, British Columbia
Year, Model & Trim Level
1999 Explorer Sport 4X4
DTC Code P0304

--------------------------------------------------------------------------------
DTC Code:

P0304

Description: Cylinder 4 Misfire Detected

Probable Causes:

1.Update control unit software - Check for the latest control unit update
2.Powertrain or Engine Control Module faulty
3.Fuel injector(s) faulty
4.Ignition system - Ignition module, coil, spark plugs and wires
5.Fuel system

Since you've taken care of number 4 I'm leaning towards number 3, a bad fuel injector or it's wiring.

It can't hurt to check number 1, control unit software update either but I'd be more inclined to think it's a mechanical problem than electronic i.e. the injector.
 




Top