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P0304

P0304 means the engine computer has detected a severe misfire on cylinder 4. This could be due to a bad ignition coil, spark plug, fuel injector, or valve train issue. If the issue is not resolved, further damage to the...

It sounds like you may need an ignition control module. It's a small device mounted around the right front of the engine compartment. It has a plug with about a dozen wires connected. The module has a separate channel for...

Hi there. The cost of the repair would depend on the problem that is causing the misfire on the #4 cylinder. It can be as simple as needing a new spark plug to as expensive as an engine rebuild if...

The two Diagnostic Trouble Codes, P0304 (https://www.yourmechanic.com/article/p0303-obd-ii-trouble-code-cylinder-3-misfire-detected-by-spencer-clayton) and P0302 (https://www.yourmechanic.com/article/p0302-obd-ii-trouble-code-cylinder-2-misfire-detected-by-jamahl-walker), refer to cylinder misfiring. A faulty ignition coil, spark plug, wire, and so forth can cause a cylinder to misfire but there are other possible causes, too. Consequently, the only...

This may be related to fuel injectors not receiving the correct current or a faulty or dirty idle air control valve. As you know, the fuel injectors receive a certain electrical pulse that allows them to spray the correct amount...

Hello. If the spark plug and the coil have been replaced, then a compression test (https://www.yourmechanic.com/article/how-to-do-a-compression-test-by-robert-tomashek) needs to be done. It is common for the valve seat to fail and cause this. When it fails, it causes low compression which...

Code P0340 (https://www.yourmechanic.com/article/p0303-obd-ii-trouble-code-cylinder-3-misfire-detected-by-spencer-clayton) is a camshaft sensor fault. The cam sensor is responsible not only for determining cam position, but it also is used by the engine computer for cylinder identification to set up both ignition firing sequence and sequential...

The code P0304 is a misfire on cylinder number four. The reason it is misfiring at cruising speed is that is when the engine is running its leanest and the coil is finding an easier path to ground than through...

Since you are getting a misfire code on the #4 cylinder that will cause the computer to shut off these other systems. The misfire needs to be fixed first. Most of the time when this comes up it is caused...

The codes all reference engine misfires. Continued misfires can cause the catalyst to fail and block the exhaust. The past diagnosis you had that the coils could be bad was correct. The coils (https://www.yourmechanic.com/services/ignition-coil-replacement) and plugs should be replaced (https://www.yourmechanic.com/services/spark-plugs-replacement)...

Hi there. The issue that maybe happening is the are fuel injectors that are not firing and there is a vacuum leak on the engine. Possible multiple sensors are not working causing the P2196 (https://www.obd-codes.com/p2196) and P2198 (https://www.obd-codes.com/p2198) codes to...

Hi there. It would appear you have covered all the bases replacing components for your P0304 (https://www.yourmechanic.com/article/p0303-obd-ii-trouble-code-cylinder-3-misfire-detected-by-spencer-clayton) engine misfire. As you already know, replacing components can be expensive and time consuming without resolution. Assuming the engine is mechanically sound, good...

Hi there. Based on what you've described, this could be a combination of faults between 2 or more things; however, I don't believe the coils and spark plugs are at fault. One of the codes is set during a low...

The codes P0300 through P0306 are for misfires of random cylinders or different cylinders. The second code P1456 is for the evaporative fuel tank system having a leak somewhere in the system (https://www.yourmechanic.com/article/how-to-diagnose-a-fluid-leak-by-mark-vallet). Since you are getting random misfires, then...

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...