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P0302 is a diagnostic trouble code (DTC) for "Cylinder 2 Misfire Detected". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
Cylinder 2 misfire detected
Most vehicles have either 4 or 6 cylinders. Each cylinder fires a spark plug one after another. A spark plug is located on the top of each cylinder. The spark plug uses an electric spark to ignite the flammable air/fuel mixture, producing energy.
The energy released by the fuel combustion powers the crankshaft. All of the cylinders work together to regulate the rotation of the crankshaft. As each cylinder fires, the crankshaft is able to rotate continuously. This process is what what makes the vehicle run smoothly.
The crankshaft revolutions per minute (RPM) may increase or decrease if a cylinder misfires. If the percentage of that increase or decrease becomes greater than 2 percent, the powertrain control module will store a trouble code.
If the crankshaft revolutions per minute have increased or decreased between 2 percent and 10 percent, the Check Engine Light will come on. If the crankshaft revolutions per minute have increased or decreased more than 10 percent, the Check Engine Light will blink. 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.
Uses the OBD-II scanner to collect freeze frame data and trouble codes stored by the powertrain control module
Checks to see if the P0302 trouble code comes back by test driving the car
Inspects the spark plug wire for cylinder 2 for wiring that is worn out or damaged
Inspects spark plug cylinder 2 itself for excessive wear or damage
Inspects the coil pack wires for wiring that is worn out or damaged
Inspects the coil packs for excessive wear or damage
If necessary, replaces damaged spark plugs, spark plug wires, coil packs, and coil pack wiring
If the P0302 trouble code returns after replacing any damaged spark plugs, coil packs, spark plug wires, and coil pack wiring, they will inspect the fuel injectors and fuel injector wiring for damage.
For vehicles with the distributor cap and rotor button system (older vehicles), they will inspect distributor cap and rotor button for corrosion, cracks, excessive wear, or any other damage.
Diagnose and repairs any other related trouble codes stored by the powertrain control module. Conducts another test drive to see if the P0302 trouble code comes back again.
If the P0302 trouble code returns, an inspection of the cylinder 2 compression system will be done (this is not common).
If the P0302 trouble code is still unresolved, a problem with the powertrain control module is possible (this is not common). Replacement or reprogramming may be necessary.
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. Addressing them during this process will save a lot of time.
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.
When one of the spark plugs needs to be replaced, replace the other spark plugs as well. If one of the coil packs needs to be replaced, it is not necessary to replace the other coil packs as well. This type of code is usually an indication that the car needs a tune up, so replacing one spark plug will normally not resolve the problem.
In order to make a quick determination about whether a faulty wire or coil pack is causing the misfiring problem, switch the wires or coil pack for cylinder 2 with another cylinder’s wires or coil packs. If a trouble code for that cylinder is stored by the powertrain control module, this indicates that the wire or coil pack is causing the misfire. When other trouble codes related to the misfiring issue are present, these need to be diagnosed and repaired as well.
Be sure that the spark plugs have been properly gapped. Use a feeler gauge to ensure a precise gap between the spark plugs. Failing to accurately gap the spark plugs, will result in another misfire. The spark plugs should be gapped according to the specifications set by the manufacturer. These specifications can usually be found on a sticker under the hood of the vehicle. If not, these specifications can be obtained from any local auto part store.
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