📖 What Does P0303 Mean?
The engine control module has detected a misfire specifically in cylinder 3. This means the air/fuel mixture in cylinder 3 is not igniting properly.
Symptoms
Rough idle, engine shaking, loss of power, flashing check engine light during acceleration, poor fuel economy.
Common Causes
Faulty spark plug in cylinder 3, bad ignition coil, clogged fuel injector, low compression, carbon buildup, vacuum leak affecting cylinder 3.
Possible Solutions
Replace spark plug for cylinder 3, swap ignition coil with another cylinder to test, clean fuel injector, perform compression test, remove carbon deposits.
Recommended Parts & Tools
Find the right parts for your P0303 repair on Amazon
📦 Parts Needed
💡 Pro Tip: Always verify part compatibility with your specific vehicle year, make, and model before purchasing.
As an Amazon Associate, CarMedic earns from qualifying purchases. This helps us maintain our free diagnostic database.
Frequently Asked Questions about P0303
How serious is P0303?
This code has a high severity level. You should address this issue immediately to prevent engine damage.
Can I drive with P0303?
Driving with this code is not recommended as it may cause further engine damage.
How much does it cost to fix P0303?
Repair costs vary depending on the root cause, but typically range from $200-500 including parts and labor.
Related Diagnostic Codes
Other codes that may appear with P0303
System Too Lean Bank 1
System Too Lean Bank 2
Random/Multiple Cylinder Misfire Detected
Cylinder 1 Misfire Detected
Cylinder 2 Misfire Detected
Cylinder 4 Misfire Detected
💡 Why These Codes Are Related:
- • Similar Issues: Same root cause or component failure
- • Related Problems: Often occur together due to system interactions
- • Sequential Codes: Progressive failure stages or multiple sensors
- • Same System: Components within the same automotive system