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P0302 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

A P0302 code means that cylinder 2 is misfiring. A misfire happens when fuel burns improperly. This can be caused by faulty ignition systems, fuel systems, or internal engine failure. 

Meaning

Most vehicles have either 4 or 6 cylinders with a spark plug on top of each cylinder. The spark plug uses an electric spark to ignite the flammable air/fuel mixture, producing energy that powers the crankshaft. As each cylinder fires, the crankshaft is able to rotate continuously. 

The crankshaft revolutions per minute may increase or decrease if a cylinder misfires. That misfire can either cause the powertrain control module will store a trouble code or the check engine light will come on. A blinking Check Engine Light indicates a more serious misfiring problem. The P0302 trouble code is an indication that cylinder 2 is misfiring and is not getting the necessary spark to its spark plug.

Causes

A car engine is a very complex part. Many things can cause misfires and a trouble code P0302. Cylinder 2 can have both a defective spark plug or lack of compression. Corrosion and damaged spark plugs need to be replaced. Damaged or worn-out spark plug wires and/or coils

Distributor caps and rotor buttons can be damaged or worn out but this does not apply to all vehicles.

Fuel-burning can be affected by defective fuel injectors. Clogged EGR valves and tubes disrupt the amount of fuel to the engine to be burned. There are also chances of the valves being burned by the fuel itself. This brings both leaks and cauterizes the valve. A harder issue to spot would be an ignition timing problem. Sensors can be issued as well. Camshaft, crankshaft, mass air-flow, oxygen, and throttle position are different sensors that will need to be tested. It can also be caused by harder to notice parts such as leaking head gaskets, damaged distributor caps and bad catalytic converters.

Symptoms

There are ways to notice problems before the P0302 diagnosis. The check engine light is the easiest to spot. Cars can not start or die randomly. Your engine can run rough or have issues with acceleration. This includes having a lack of power while driving. An increase in fuel consumption is something that can cause the other symptoms but also be a symptom itself.

Diagnosis

Use the OBDII scanner to see the trouble code diagnosis. If the P0302 trouble code comes back by test driving the car. Afterward, inspects the spark plug wire for cylinder 2 and cylinder 2 itself for damage. Repeat the process for coil pack wires and the coil pack. Replace all the damaged and worn components. If the P0302 trouble code returns after replacing damages, they will inspect the fuel injectors and fuel injector wiring for damage. Then inspect the distributor cap and the rotor button. Diagnose and repair any other related trouble codes stored by the powertrain control module. If the trouble code persists, inspect the cylinder 2 compression system. If the P0302 trouble code is still unresolved, a problem with the powertrain control module is possible.

Common mistakes

Visually inspect the fuel injector wiring for damage before replacing spark plugs, coil packs, or spark plug and coil pack wiring. If applicable, diagnose and repair any other related trouble codes that are present. Also, make sure to rule out a faulty cylinder as the cause of the problem. Any of these components could result in the P0302 trouble code. It is important to take the time to rule out all possible causes of the misfire code during diagnosis.

How serious is this?

The P0302 trouble code is considered serious. Some of the symptoms of this code make the operation of the vehicle dangerous. The vehicle may stop abruptly or stall out. In addition, damage to other engine components is possible if the trouble code is left unaddressed. For these reasons, the P0302 trouble code requires immediate attention.

What repairs can fix the code?

The majority of the repairs are fixed by replacing or repairing a piece. You can replace spark plugs, spark plug wires, coil pack wires, distributor caps and EGR valves and tubes. Many of the sensors need to be diagnosed and inspected before replacing them. Vacuum leaks, leaking head gaskets and fuel injectors can be repaired. Bigger items that will need to be replaced will be fuel injectors, catalytic converters and the engine (if there is cylinder damage). In rare cases, the powertrain control module may need to be replaced or reprogrammed.

There are other codes similar to the P0302 code. All tweets from P0301 to P0312 are codes similar to misfire on a particular cylinder. For more information, visit our website and look for other codes you may be experiencing.