2007 Mitsubishi P0303: What It Means & Is It Safe to Drive?
P0303 on the 2007 Mitsubishi: Cylinder 3 Misfire Detected. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
What this code means
The PCM has detected a misfire specifically on cylinder 3. Diagnosis follows the same steps as P0301—swap parts to the same position on a known-good cylinder to isolate the fault.
Common causes on the 2007 Mitsubishi
- Worn or fouled spark plug on cylinder 3
- Failing ignition coil on cylinder 3
- Leaking or clogged fuel injector
- Low compression on cylinder 3
Symptoms
- Check Engine Light, often flashing under load
- Rough idle or shaking
- Loss of power, hesitation
Typical fixes
- Replace spark plug and coil on cylinder 3
- Test and replace fuel injector
- Compression test if ignition parts don't resolve it
Repair cost range
For a 2007 Mitsubishi, repairs for P0303 typically fall between $150 and $900, depending on the root cause and labor rates in your area.
Known issues on Mitsubishi
Mitsubishi V6 P0303 on cylinder 3 (rear bank) typically means a failed coil-on-plug. On the 3.8L 6G75 in Eclipse and Endeavor, rear-bank coil access requires intake manifold removal. Confirm the fault with a coil swap to the front bank first.
Most commonly affected models