Can You Drive With a Misfiring Engine? What the Risks Are

Your engine is misfiring and the check engine light is on. Can you keep driving? The answer depends on how bad the misfire is and how far you need to go. Here's what you need to know.

The Risk of Continued Driving

Catalytic Converter Damage

This is the most serious near-term risk. A misfiring cylinder sends raw, unburned fuel into the exhaust. The catalytic converter is not designed to process this fuel — it overheats and the catalyst material inside is destroyed. Catalytic converter replacement costs $800–$2,500 or more. A check engine light that's flashing (not solid) means a catalytic converter-damaging misfire is occurring — stop driving.

Ignition Coil Damage

When a cylinder misfires due to a bad spark plug, the ignition coil has to work harder trying to fire it. This thermal stress can burn out the coil. A $15 plug becomes a $100+ coil.

Oxygen Sensor Damage

Excess unburned hydrocarbons in the exhaust can contaminate and damage oxygen sensors over time.

Flashing vs Solid Check Engine Light

• Flashing/blinking light: Stop driving. Active catalytic converter damage is occurring. This is a serious, immediate situation.
• Solid light: Drive carefully to a shop or home. Avoid heavy acceleration. Get it diagnosed within a day or two.

What to Do

If the light is solid and the car drives reasonably well, you can typically drive short distances carefully to get parts and fix it. If the light is flashing or the car stumbles severely, get it off the road and fix it before driving further.

Shop spark plugs at Texan Supply with free shipping — get the fix in before it cascades.