Cylinder 2 Misfire Detected
P0302 indicates that the engine control module (ECM) has detected a misfire in cylinder 2. A misfire occurs when the air-fuel mixture in the cylinder fails to ignite properly, causing a loss of power, increased emissions, and potential damage to the catalytic converter. Common causes include faulty spark plugs, ignition coils, fuel injectors, vacuum leaks, or low compression. Prompt diagnosis is recommended to prevent further engine damage.
01. Most Common Causes
- Faulty spark plug or ignition coil on cylinder 2
- Clogged or leaking fuel injector on cylinder 2
- Vacuum leak affecting cylinder 2
- Low compression in cylinder 2 (e.g., worn piston rings, burnt valve)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine runs rough, especially at idle or under load
- Reduced power and acceleration
- Increased fuel consumption
03. Step-by-Step Diagnosis
Step 1: Scan for codes and note freeze frame data.
Step 2: Swap spark plug and ignition coil from cylinder 2 to another cylinder; if misfire moves, replace the faulty component.
Step 3: Check fuel injector operation on cylinder 2 using a noid light or multimeter.
Step 4: Perform a compression test on cylinder 2 to rule out mechanical issues.
Step 5: Inspect for vacuum leaks using a smoke machine or propane enrichment.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with a misfire, as it can damage the catalytic converter and cause further engine problems. If the engine is running rough, have it towed to a repair shop.
How much does it cost to fix?▼
The cost varies depending on the cause. A spark plug replacement can cost $50-$150, while an ignition coil may be $100-$200. Fuel injector or compression repairs can be more expensive.