P0303 2017 GMC Sierra Code - Cylinder 3 Misfire Detected
Quick Answer
The diagnostic trouble code P0303 for a 2017 GMC Sierra indicates that a misfire has been detected in cylinder 3 of the engine. Common causes include Faulty spark plug in cylinder 3, Failing ignition coil in cylinder 3, Clogged or malfunctioning fuel injector in cylinder 3. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0303 2017 GMC Sierra indicates Cylinder 3 Misfire Detected.
- Common causes
- Common causes include Faulty spark plug in cylinder 3, Failing ignition coil in cylinder 3, Clogged or malfunctioning fuel injector in cylinder 3.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P0303 2017 GMC Sierra Description
The diagnostic trouble code P0303 for a 2017 GMC Sierra indicates that a misfire has been detected in cylinder 3 of the engine. A misfire occurs when the fuel-air mixture in the cylinder fails to ignite at the proper time, causing a disruption in the combustion process. This can lead to a loss of power, rough idling, decreased fuel efficiency, and increased emissions.
Common Causes of P0303 2017 GMC Sierra
- Faulty spark plug in cylinder 3
- Failing ignition coil in cylinder 3
- Clogged or malfunctioning fuel injector in cylinder 3
- Vacuum leak affecting cylinder 3
- Low compression in cylinder 3
Symptoms of P0303 2017 GMC Sierra
- Engine misfiring or running rough
- Loss of power or acceleration
- Rough idling or vibrations
- Check Engine Light illuminated
- Increased fuel consumption
How to Fix P0303 2017 GMC Sierra
- Begin by diagnosing the specific cause of the misfire in cylinder 3 using a scan tool to check for any other related trouble codes.
- Inspect and replace the spark plug in cylinder 3 if it is found to be faulty.
- Test the ignition coil in cylinder 3 and replace it if necessary.
- Check the fuel injector in cylinder 3 for clogs or malfunctions and clean or replace it as needed.
- Inspect for vacuum leaks in the intake manifold or vacuum lines that may be affecting cylinder 3 and repair as necessary.
Cost to Fix P0303 2017 GMC Sierra
The cost of repairing a cylinder 3 misfire in a 2017 GMC Sierra can vary depending on the specific cause of the issue and the labor rates in your area. On average, you can expect to pay anywhere from $100 to $500 for parts and labor. Keep in mind that diagnostic time and labor rates can vary, so it's best to get a quote from a reputable auto repair shop in your area.
Tech Notes for P0303 2017 GMC Sierra
There is a Factory Service Bulletins for All 2000-2020 Chevrolet Models:
2000-2020 Chevrolet Factory Service Bulletin OBDII Code P0303
This Factory Service Bulletin explains how this condition may be caused by significant carbon build-up on the intake and/or exhaust valves due to fuel contamination or incomplete burning of the fuel.
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Frequently Asked Questions about P0303 2017 GMC Sierra Code
What does OBDII code P0303 mean for a 2017 GMC Sierra?
P0303 indicates a misfire has been detected in cylinder 3 of the engine.
What are the common symptoms of code P0303 in a 2017 GMC Sierra?
Symptoms may include rough idling, reduced engine power, poor fuel efficiency, and the Check Engine Light illuminated.
What causes code P0303 in a 2017 GMC Sierra?
Common causes include a faulty spark plug, a malfunctioning ignition coil, a clogged fuel injector, low cylinder compression, or vacuum leaks near cylinder 3.
Can driving with code P0303 damage my 2017 GMC Sierra?
Yes, prolonged driving with a misfire can cause damage to the catalytic converter and other engine components.
How can I diagnose code P0303 in a 2017 GMC Sierra?
Start by inspecting the spark plug, ignition coil, and fuel injector for cylinder 3. You may also need to perform a compression test or check for vacuum leaks.
How do I fix code P0303 on a 2017 GMC Sierra?
Repairs may include replacing the spark plug or ignition coil for cylinder 3, cleaning or replacing the fuel injector, or addressing any mechanical issues like compression problems.
Is replacing the spark plug enough to fix code P0303 in a 2017 GMC Sierra?
Replacing the spark plug may resolve the issue if the misfire is caused by a worn or faulty plug, but other components like the ignition coil or fuel injector may also need attention.
Can bad fuel cause code P0303 in a 2017 GMC Sierra?
Yes, low-quality or contaminated fuel can lead to misfires, including in cylinder 3.
How much does it cost to repair code P0303 on a 2017 GMC Sierra?
Repair costs can vary widely, from $50 for a spark plug replacement to several hundred dollars for more complex fixes like addressing a fuel injector or compression issue.
Can a dirty air filter trigger code P0303 in a 2017 GMC Sierra?
A dirty air filter is unlikely to directly cause this code but can contribute to overall engine performance issues that may exacerbate a misfire.
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