2021 GMC P0302: What It Means & Is It Safe to Drive?
P0302 on the 2021 GMC: Cylinder 2 Misfire Detected. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
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What this code means
The PCM has detected a misfire on cylinder 2. Same logic as P0301, but for a different cylinder.
Common causes on the 2021 GMC
- Worn or fouled spark plug on cylinder 2
- Failing ignition coil
- Leaking or clogged fuel injector
- Low compression on cylinder 2
Symptoms
- Check Engine Light
- Noticeable shaking, especially at idle
- Loss of power or hesitation
Typical fixes
- Replace spark plug/coil on cylinder 2
- Clean or replace injector
- Address internal engine problems if compression is low
Repair cost range
For a 2021 GMC, repairs for P0302 typically fall between $150 and $900, depending on the root cause and labor rates in your area.
Known issues on GMC
GMC Sierra 5.3L P0302 is a non-AFM cylinder, so coil or plug failure is the typical cause. On the 3.7L inline-five Canyon, P0302 is more common than on V8 models—individual coil failures occur regularly past 80k miles on this engine.
Most commonly affected models
Sierra 5.3L 2007–2014Canyon 3.7L I5 2004–2012Terrain 2.4L 2010–2017