What is the meaning of OBD-II code P0304, and what are the possible causes and solutions for this code to be generated?

The P0304 code is an indication that the electronic control unit (ECU) has detected an issue with the functioning of cylinder 4. The ECU continuously monitors the performance of all cylinders to guarantee they are firing in a timely manner. When one cylinder experiences repeated misfires, the Check Engine Light is triggered. There are several possible causes for a P0304 code, such as: -Defective spark plug -Defective wires, cap, rotor, or coil pack -Engine malfunction -Leak in the intake system -Fuel problems To diagnose the problem, a mechanic will typically use a scan tool to hook up to the DLC port, clear codes, perform a road test, visually inspect for damage or leaks, monitor the misfire counter for cylinder 4, and check long-term fuel trims and intake air pressure for fuel or vacuum issues. The resolution to the P0302 code will vary based on the underlying cause, which may involve replacing the spark plugs, replacing the cap and rotor, coil pack, and plug wires (as required by the vehicle), repairing any engine mechanical problems, fixing any air leaks, or fixing any fueling faults. A comprehensive scan tool with the capability to access live engine data is essential for accurately diagnosing P0304. This tool should display not only the code but also allow monitoring of misfires, fuel, and intake information.