Q: Cylinder 3 is misfiring

asked by on March 21, 2016

I am getting a Check Engine code P0303, which is a misfire on cylinder 3. I am not exactly sure whether the cylinder needs cleaning or replacing, or if it is just a spark plug.

Misfire on cylinder 3 usually mean you have a bad spark plug or spark plug wire. If you haven’t had a tune up in a while I would recommend having a technician, such as one from YourMechanic, come out and replace your spark plugs, wires, and air filter and see if that helps. I would also have them replace the fuel filter as well since a misfire may be caused by the fuel system as well.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

The clutch pedal doesn't spring back as quickly when it is cold outside.

Hi there. It is possible that the brake fluid may be freezing. When brake fluid gets old, it collects too much moisture causing water droplets to form in the fluid. This will gel up the fluid and cause it to...

Car makes scraping sound and rattles

Replacing the transmission fluid and filter is part of the manufacturer's recommended service that should be done at intervals for regular maintenance. The transmission can have issues such as this when it is failing, low fluid level, torque converter malfunctions,...

When I stop my car it starts to turn off. When I run my car for a bit and turn it off, it won't turn back on when I twist the key.

Hello. If the car doesn't crank then there is likely an issue with the starting or electrical system. If the issue began after you installed the new battery then the first thing I would do is check the battery to...

Related articles

What Are the Best Spark Plugs for Normal Use?
Spark Spark plugs are essential components of your ignition system. They’re responsible for supplying the spark that ignites fuel and starts the combustion process. However, not all spark plugs are created equal. You’ll find “normal” plugs on the market, but...
The Best Used Cars to Buy For Fuel Economy
Saving money on gas is an important factor to consider when buying a car. The Honda Civic, Toyota Prius, and Ford Fusion all have great fuel economy.
How Often Should Spark Plugs Be Replaced?
While your engine runs on gasoline, it also requires electricity. It’s needed to operate most of your accessories, but is also required to...