Q: Check Engine light P0304.

asked by on February 04, 2016

I am getting a Check Engine light code P0304. I've already had all the spark plugs replaced and coil number 5.

The code P0304 points to a misfire on cylinder number 4. Ford also has a funny cylinder identification pattern, different from many makes, and a diagram should be consulted to determine which cylinder is the right one. The spark plugs have been changed, now suspect the coil on cylinder number 4 or its wiring. A mechanic, like the ones here at YourMechanic, would be more than happy to assist you with an inspection on this engine misfire.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

I'm looking for the heater blower fuse (30 amp)

The 1991 E250 Econoline does not use a fuse, but a blue fusible link wire that is off of the yellow wire, which comes off of the power side of the starter relay on the fender. This then goes straight...

Ford Ranger idle roughly

These engines were known to get a carbon build up on the intake valves and the excessive carbon buildup will soak up any fuel the injectors spray when it is first started until it gets warmed up. The buildup can...

The metal piece that attaches the rear windshield wiper to the car

Hey there. This piece is called the wiper arm. They can be purchased from most auto parts stores. If you need to have a wiper arm replacement taken care of for you, a qualified technician from YourMechanic can come to...

Related articles

P2574 OBD-II Trouble Code: Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Low4
P2574 code means the degree of ozone reduction for each catalytic converter is not where it should be due to oxygen or pressure sensors.
P0471 OBD-II Trouble Code: Exhaust Pressure Sensor Range/Performance
P0471 means the powertrain control module has detected an voltage that is out of the normal range due to the exhaust back pressure system.
P2667 OBD-II Trouble Code: Fuel Shutoff Valve B Control Circuit High
P2667 means there is a problem with the fuel shut off valve usually after a rear end collision or other electrical issues or problem.