p0303
Moderate
Chevrolet · SUVs
Cylinder 3 Misfire Detected
Quick Answer
Error code P0303 on your Chevrolet SUVs means: Cylinder 3 Misfire Detected. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
CL14636CL14606Blazer LT 2024Blazer Premier 2024Blazer RS 2024Equinox Activ 2024Equinox LT 2024Equinox RS 2024Suburban High Country 2024Suburban LS 2024Suburban LT 2024Suburban Premier 2024Suburban RST 2024Tahoe High Country 2024Tahoe LS 2024Tahoe LT 2024Tahoe Premier 2024Tahoe RST 2024Tahoe Z71 2024Trailblazer Activ 2024Trailblazer LS 2024Trailblazer LT 2024Trailblazer RS 2024Traverse LS 2024Traverse LT 2024Traverse Premier 2024Traverse RS 2024Traverse Z71 2024Trax Activ 2024Trax LS 2024Trax LT 2024Trax RS 2024CL14526CL14506CK10906CK10706CL14456CL14806CL14416
Likely Causes
How to Fix It
1
Swap the cylinder 3 ignition coil with an adjacent cylinder and check if the misfire moves
2
Replace the cylinder 3 spark plug and check for fouling or damage on the old plug
3
Test the cylinder 3 fuel injector for proper resistance and spray pattern
4
Perform a compression test on cylinder 3 and compare to adjacent cylinders
5
Inspect for vacuum leaks near the cylinder 3 intake runner
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Spark plug
Ignition coil pack
Fuel injector
Intake manifold gasket (if vacuum leak found)
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