P0307 - CYLINDER 7, MISFIRE DETECTED

A misfire is caused by a cylinder that is not firing as it should. In this case, the DTC code P0307 OBD2 is stored due to an ignition failure in cylinder 7.

Different manufacturers implement OBDII requirements. One of these is the misfire monitor, which is based on changing the crankshaft speed. To determine the crankshaft speed, the PCM uses the information provided by the Camshaft position sensor (CMP) and the Crankshaft position sensor (CKP). When a cylinder fails, it momentarily slows down since the CKP and CMP sensor signals are monitored by the PCM, which can calculate when an ignition failure occurs.

• Check Engine Lighting.
• A difficult start.
• It lowers fuel efficiency.
• Idle vibration.

Fault code P0307 OBDII is activated by:

• Number 7 cylinder cables with defects.
• The spark plug in the number 7 cylinder may be damaged.
• The fuel pump may be in bad shape.
• The coil of cylinder number 7 could be defective.
• The fuel injector of cylinder number 7 may be faulty.

When faced with the diagnostic code P0307 OBD2, take into account the following:

• If no symptoms are present, clear the code and see if it returns.
• Inspect the system of cables and connectors leading to the spark plugs. It is recommended to change these ignition components as part of a maintenance program. These include the spark plugs with their wires, the distributor cap, and the rotor. Repair or replace as necessary.
• Change the cat of the Catalytic Converter.