Standardized generic DTCIgnition & misfire

P0314 — Single Cylinder Misfire — Cylinder Not Specified

P0314 is the standardized powertrain DTC for “Single Cylinder Misfire — Cylinder Not Specified.” The code identifies the monitored condition; it does not by itself prove which part failed.

Standardized generic definition

Single Cylinder Misfire — Cylinder Not Specified

DTC category

Ignition & misfire

Diagnostic priority

High if the MIL is flashing or the engine is running roughly — continued driving can overheat the catalytic converter.

Copy code

What P0314 means

P0314 is the standardized powertrain DTC for “Single Cylinder Misfire — Cylinder Not Specified.” The code identifies the monitored condition; it does not by itself prove which part failed.

Start with the stored data and the simplest external checks before replacing the component named in the code.

Possible symptoms

Flashing or steady Check Engine Light
Rough idle, hesitation, loss of power
Fuel odor or poor fuel economy
Possible hard starting

Causes to test

These are diagnostic possibilities, not a statistical parts-replacement ranking. Vehicle-specific service information takes priority.

Ignition problem: worn plug, damaged coil/boot, excessive plug gap, or wiring fault
Fuel delivery problem: injector fault, low fuel pressure, contaminated fuel, or injector imbalance
Unmetered air/vacuum leak or incorrect air measurement
Low compression, valve-train problem, timing issue, or other mechanical fault
On some vehicles, software/calibration or known service-bulletin condition

Step-by-step diagnostic workflow

Do not clear codes; record freeze-frame and misfire counters first.
If the MIL is flashing, avoid sustained driving and load.
Identify whether the misfire is confined to one cylinder or affects multiple cylinders.
For a single-cylinder misfire, inspect plug/coil/injector and compare that cylinder with a known-good cylinder where service procedures permit.
Check fuel pressure, fuel trims, MAF/MAP data, and for intake leaks if multiple cylinders are affected.
If ignition and fuel tests pass, perform compression/leak-down or valve-train/timing checks as appropriate.
After repair, verify misfire counters remain stable during idle, cruise, and load.

Preserve evidence: EPA OBD guidance emphasizes that stored DTCs and freeze-frame data are important to proper diagnosis. Save them before clearing codes.

Scan data worth checking

Cylinder-specific misfire counters
Short- and long-term fuel trims
Engine load, RPM, coolant temperature, and spark advance
Fuel pressure or commanded rail pressure where supported

Severity and drivability

High if the MIL is flashing or the engine is running roughly — continued driving can overheat the catalytic converter.

Stop driving and investigate immediately if there is a flashing MIL, oil-pressure warning, overheating, fuel leakage, severe misfire, major loss of power, abnormal mechanical noise, or a transmission that is slipping badly.

Common diagnostic mistakes

Replacing all coils or injectors without isolating the affected cylinder
Continuing to drive with a flashing MIL
Condemning the catalytic converter before correcting an active misfire

Related generic codes

P0313 — Misfire Detected With Low FuelP0312 — Cylinder 12 Misfire DetectedP0316 — Misfire Detected on Startup — First 1,000 RevolutionsP0311 — Cylinder 11 Misfire DetectedP0310 — Cylinder 10 Misfire DetectedP0309 — Cylinder 9 Misfire Detected

Source and accuracy notes

Generic DTC structure and standardized definitions are governed by SAE J2012/J2012DA. Actual enable criteria, thresholds, circuit pinouts, test values, software conditions, and repair procedures vary by vehicle. Use current OEM service information for the exact year/engine/calibration and check applicable manufacturer technical service bulletins. See the site methodology and primary-reference policy.