P02C4
Cylinder 11 - Injector Restricted
Fuel & air metering
Generic OBD-II
High
What it means
P02C4 means the fuel injector on cylinder 11 is restricted — it can't flow the fuel the module expects, usually from clogging or deposits. That leaves cylinder 11 running lean, which shows up as rough running or a misfire. It's typically resolved by cleaning or replacing the affected injector rather than by clearing the code.
High
Can I keep driving? The engine runs, but a restricted cylinder-11 injector starves that cylinder of fuel — expect rough running and possible misfire, so address it before it worsens.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or a misfire on cylinder 11
- Hesitation or reduced power under load
- Hard starting or a lean condition on that cylinder
Common causes
Most likely first
- Clogged or restricted fuel injector on cylinder 11Likely
- Fuel deposits or contamination narrowing the injector sprayCommon
- Low or uneven fuel pressure reaching the injectorCommon
- Poor-quality or dirty fuelLess often
- Weak injector coil or partial internal faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check cylinder-11 fuel trim and any misfire counts.
- Run an injector-balance or flow test to confirm cylinder 11 is delivering less fuel.
- Try a professional injector cleaning or a quality detergent additive for light restriction.
- Verify fuel pressure and rule out a supply restriction.
- Replace the cylinder-11 injector if cleaning doesn't restore flow, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P02C4?+
Short term yes, but a restricted injector leans out cylinder 11 and can misfire, risking catalytic-converter damage over time. Repair it soon.
Can I just clear P02C4?+
It returns as the injector stays restricted. Cleaning or replacing the injector is what clears the fault for good.
Related codes
Often seen with P02C4
Read & clear P02C4 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX