OBD-II Error Code P0312: How to Fix Cylinder 12 Misfire

Q: Can I still drive with a P0312 code?

It is not recommended. Driving with a misfire can damage the catalytic converter and cause other engine problems. Have it diagnosed as soon as possible.

Q: What are common causes of cylinder 12 misfire?

Common causes include faulty spark plugs, ignition coils, fuel injectors, vacuum leaks, or low compression in that cylinder.

Q: Is P0312 the same as P0300?

No. P0300 indicates random or multiple cylinder misfires, while P0312 specifically points to cylinder 12 misfire.

Q: How do I know which cylinder is number 12?

Cylinder numbering varies by engine. For V12 engines, cylinder 12 is typically on the passenger side rear. Check your vehicle's repair manual for cylinder layout.

Q: Will a bad O2 sensor cause P0312?

No, a bad O2 sensor usually triggers different codes (P0420, P0430, etc.). It is unlikely to cause a specific cylinder misfire code like P0312.

Abstract

Error code P0312 indicates that your vehicle's engine control module (ECM) has detected a misfire in cylinder 12. A misfire can cause rough idling, poor acceleration, increased emissions, and potential damage to the catalytic converter. This guide will help you diagnose and fix the issue step by step.