Why is P0300 dangerous?

Misfire can cause unburned fuel to burn in the catalyst; it overheats and gets damaged. Performance drops and emissions rise.

Can I drive with P0300?

Not recommended. If necessary, short distance at low revs and light load only; then get to a shop as soon as possible.

What if P0300 and P0171 appear together?

Fix the mixture (P0171) first. Lean mixture often causes misfire; fixing P0171 may clear P0300 as well.

P0300 OBD2 Error Code: Random/Multiple Cylinder Misfire Detected

Category: Ignition and misfire · Last updated: February 1, 2026

What does this error code mean?

Random/Multiple Cylinder Misfire Detected

Common symptoms

Check engine light on (sometimes with flashing)
Engine roughness at idle or during acceleration
Loss of power, weak throttle response
Increased fuel consumption

What causes it?

Worn or faulty spark plugs, coils, or plug wires
Low fuel pressure, dirty filter, or faulty injectors
Air leak or MAF fault (P0171, P0172, etc.)
Low compression (worn rings, burned valve)
Ignition timing error or crankshaft sensor fault

How to fix

Inspect and replace spark plugs and coils if worn
Check fuel pressure, filter, and injectors; clean or replace as needed
Check for vacuum leaks and MAF; fix mixture codes first if present
Perform compression test; engine rebuild may be needed if mechanical fault

Is it safe to drive?

Driving with P0300 is not recommended. Misfire damages the catalyst, increases emissions, and reduces performance. Heavy load or high revs increase risk. Get it diagnosed and repaired as soon as possible.

Estimated repair cost

Estimated cost range (labour and parts): 800 – 6,000 TL. Plug/coil replacement 800–2500 TL; fuel system or injector work 2000–4000 TL; mechanical repairs may cost more.

Expert opinion

Check spark plugs and ignition coils first; worn plugs or faulty coils are common. Fuel pressure and injector balance must be checked. If mixture codes (P0171, P0172) exist, fix those first. Single-cylinder codes (P0301 etc.) focus on that cylinder. Listen to symptoms like rough idle or lack of power.

For information only. Content on this site is for general guidance; it does not replace professional diagnosis or repair. Always consult a qualified technician before making decisions about your vehicle.

Frequently asked questions

Why is P0300 dangerous?: Misfire can cause unburned fuel to burn in the catalyst; it overheats and gets damaged. Performance drops and emissions rise.
Can I drive with P0300?: Not recommended. If necessary, short distance at low revs and light load only; then get to a shop as soon as possible.
What if P0300 and P0171 appear together?: Fix the mixture (P0171) first. Lean mixture often causes misfire; fixing P0171 may clear P0300 as well.