A small engine misfire can quickly turn into a much bigger and more expensive problem.
If your car is misfiring, you will usually notice it right away. The engine may feel rough, the vehicle might shake when accelerating, the check engine light may flash, and the car may feel weaker than normal.
A common question drivers ask is: “How long can I keep driving like this?”
The honest answer is not very long—and in many cases, you should stop driving immediately.
What Is an Engine Misfire?
An engine misfire happens when one or more cylinders fail to ignite the air-fuel mixture correctly. Your engine depends on precise timing between fuel, air, and spark. If any part of that process fails, the cylinder cannot produce proper power.
Common causes of a misfire include:
- Worn or fouled spark plugs
- Faulty ignition coils
- Fuel injector problems
- Vacuum leaks
- Low compression inside the engine
- Fuel delivery issues
- Engine sensor failures
Modern vehicles are very good at detecting these problems, which is why a check engine light often appears quickly.
Can You Drive With a Misfire?
Technically, the car will often still run, but driving with a misfire is risky. If the misfire is minor, you might still be able to drive a short distance. However, continuing to drive can cause significant damage to other parts of the engine and exhaust system. The biggest risk is damage to your catalytic converter, which is one of the most expensive components in the emissions system. When a cylinder misfires, unburned fuel enters the exhaust system. That fuel burns inside the catalytic converter, creating extreme heat that can melt or destroy the converter internally.
A repair that may have originally been a spark plug or ignition coil can quickly become a $1,000+ catalytic converter replacement.
When You Should Stop Driving Immediately
If you notice any of the following symptoms, it’s best to stop driving and have the vehicle inspected as soon as possible:
- The check engine light is flashing
- The engine is shaking or running very rough
- The vehicle struggles to accelerate
- You smell raw fuel from the exhaust
- The engine feels like it may stall
A flashing check engine light specifically means the computer is detecting an active misfire that could damage the catalytic converter. In that situation, driving further can make the repair much more expensive.
What Happens If You Ignore a Misfire?
Ignoring a misfire can lead to several escalating problems:
- Catalytic converter failure
- Damaged oxygen sensors
- Engine overheating
- Internal engine damage
- Reduced fuel economy
- Increased emissions
In severe cases, long-term misfires can even lead to engine damage that requires major repair.
The Good News: Most Misfires Are Fixable
The good news is that many misfires are relatively simple repairs when caught early.
Common fixes include:
- Replacing worn spark plugs
- Replacing a failed ignition coil
- Cleaning or replacing a fuel injector
- Repairing a vacuum leak
The key is diagnosing the issue quickly before it causes additional damage.
Don’t Ignore the Warning Signs
If your vehicle is running rough or the check engine light is flashing, it’s best to have it inspected right away. Catching the problem early can prevent a small issue from turning into a much larger repair.
If you're in Northglenn, Thornton, Broomfield, or the surrounding Denver area, the team at Motiveworks Auto can help diagnose engine misfires and get your vehicle running smoothly again.
