Spark Plugs
Ignition Coil
Spark Plug Wires
Mass Airflow (MAF) Sensor
Compression Tester
Spark Tester
Fuel Pressure Tester
Crankshaft Position Sensor
Camshaft Position Sensor
The necessary parts and tools to clear this Diagnostic Trouble Code (DTC) might differ depending on your vehicle's make and model. If your Check Engine light is illuminated, stop by any O’Reilly Auto Parts and get an O’Reilly VeriScan® for your car, truck, or SUV and get a detailed VeriScan report with more information about your vehicle’s Diagnostic Trouble Code(s), along with possible causes and repair solutions. If you aren’t comfortable making these repairs yourself, our parts professionals can recommend a local shop to make your repair.
Technically speaking, OBD-II fault codes ranging from P0301 through P0312 indicate that a cylinder misfire is detected in one or more cylinders. In practical terms, a misfire is when a cylinder fails to produce power or combustion doesn’t occur because of a lack of spark, fuel, or compression. When you see one of these codes, the last two digits of the code will correspond with the misfiring cylinder. For example, P0301 would indicate cylinder 1, P0302 would be cylinder 2, P0303 is cylinder 3, and so on. Not all vehicles will experience all of these codes, as it is based on the number of cylinders on the engine. So, for example, a vehicle with a 6-cylinder engine would never experience a P0308 code, indicating a misfire on cylinder 8.
P0301 to P0312 Code Diagnosis
There are several potential causes for a misfire code, including issues with:
- Spark plugs
- Ignition wires
- Coils
- Distributor cap and rotor
- Ignition timing
- Vacuum integrity
- Fuel pressure
- EGR system
- Mass airflow sensor
- Crankshaft position sensor
- Camshaft position sensor
- Valves
- Head gasket
An engine misfire, fuel pressure issue, or defective oxygen sensor can lead to your catalytic converter not functioning efficiently, or the exhaust system or catalytic converter itself may have failed, and you may see additional codes that can help narrow down your diagnosis.
P0301 to P0212 OBD-II Code Symptoms
Besides a Check Engine light, you may also notice other symptoms with P0301 to P0212 codes.
Symptoms of a P0301 to P0212 Code can include:
- Check Engine light
- Rough running/idling
- Lack of power
- Hesitation or jerking
- Dying at stops
- Poor fuel economy
Whether you notice any symptoms or not, it is not recommended that you drive a vehicle with this code until the problem is diagnosed. Doing so can cause additional damage to the engine’s cylinders, pistons, or crankshaft, especially if the misfire is constant and severe.
If your Check Engine light is on, stop by any O’Reilly Auto Parts location where our Parts Professionals can scan and diagnose your illuminated Check Engine light for free with our exclusive O’Reilly VeriScan code reading service. An O’Reilly VeriScan provides a detailed report of possible causes and solutions or repairs for your illuminated Check Engine light. The O'Reilly VeriScan report, along with the O’Reilly Auto Parts How-To resources can help you understand what parts, tools, and services you need to clear your DTCs and Check Engine lights. If you aren’t comfortable performing any necessary repairs yourself, we are also happy to recommend a local repair shop.
