P0363: Misfire Detected - Fueling Disabled

What it means

Severe misfire detected — the PCM has disabled fuel injection on the affected cylinder(s) to protect the catalyst from raw fuel. Common protective response on heavy or sustained misfire conditions.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

This code indicates that the control module detected a misfire severe enough to disable fuel injection to one or more affected cylinders. Cutting fuel helps protect the catalytic converter from unburned fuel, but it also reduces engine power and can make the engine run unevenly.

Common causes

Most likely first.

1. Severe misfire on one or more cylinders
2. Ignition, fuel, or compression fault causing the misfire
3. Fault in the cylinder fuel-injection circuit

Symptoms

• Check engine light on or flashing
• Rough idle and uneven running
• Power loss, hesitation under acceleration
• Increased fuel consumption
• Possible smell of unburned fuel from exhaust

How to diagnose it

1. Check whether the check-engine light is flashing, save freeze-frame data, and note which cylinders have misfire counts or fuel-cut status.
2. Inspect the affected cylinders' ignition coils, plugs, connectors, and wiring for damage or a loose connection.
3. Check live data and the wiring diagram to confirm whether injection is disabled and inspect the affected injector circuit for a fault.
4. Test fuel delivery and injector operation on the affected cylinder or cylinders according to the manufacturer's procedure.
5. If ignition and fuel tests do not explain the misfire, check compression and mechanical timing on the affected cylinders.

Common fixes

• Repair a loose or damaged ignition or injector connector on an affected cylinder.
• Replace a failed spark plug or ignition coil identified by testing.
• Repair an open, short, or poor connection in the affected injector circuit.
• Replace a confirmed faulty injector or repair the underlying compression or mechanical fault.

Can I keep driving?

Do not continue driving with a flashing check-engine light, severe shaking, or major power loss; have the vehicle stopped safely because misfire can damage the catalytic converter and unpredictable power can be hazardous. If fuel has been cut on a cylinder, avoid driving until the cause is diagnosed.