P0300 on Chevrolet: Random or Multiple Cylinder Misfire Detected
Severity: 3 of 4
Park it if the check engine light is flashing or the engine is shaking. A flashing light means misfires severe enough to damage the catalytic converter and in extreme cases cause an exhaust fire. If the light is steady and the misfire is mild, drive only as far as needed to get it diagnosed, gently and without heavy loads.
Estimate range covers the repairs listed below; see the cost breakdown. A flashing check engine light, a hot temperature gauge, or brakes that feel different mean stop driving and get help.
What P0300 usually means on a Chevrolet
P0300 on 2014 and later Chevrolet V8 trucks and SUVs with Active or Dynamic Fuel Management can come from a failed lifter. A pending class action alleges these lifters are defective; GM disputes it. Either way it is a significant repair. A ticking noise and misfires concentrated on cylinders that deactivate are warning signs.
On other engines, plugs, coils, and vacuum leaks are more typical.
Most likely causes on Chevrolet vehicles
- Spark plugs and wires or coils
- Vacuum leak
- AFM lifter failure (V8)
- Fuel delivery
Order reflects cost and likelihood in general; your vehicle may differ. Confirm with testing before buying parts.
Chevrolet specific tips
- Do not keep driving on a flashing light; lifter failures can damage the camshaft.
- A shop can check which cylinders misfire most.
Estimated repair cost
This is an estimate, built from typical parts price ranges plus labor hours times an assumed shop rate of $110 to $190 per hour. Actual prices vary by vehicle, region, and shop. Diagnosis fees are often extra.
| Repair | Parts | Labor | Estimate (low / high) |
|---|---|---|---|
| Spark plugs, full set | $20 to $120 | 0.5 to 2.5 h | $20 + 0.5 × $110 = $75 $120 + 2.5 × $190 = $595 |
| Vacuum hose or intake gasket | $10 to $120 | 0.5 to 2.5 h | $10 + 0.5 × $110 = $65 $120 + 2.5 × $190 = $595 |
| Ignition coil, one | $30 to $150 | 0.2 to 1.0 h | $30 + 0.2 × $110 = $52 $150 + 1.0 × $190 = $340 |
| Fuel pump | $120 to $600 | 1.5 to 3.5 h | $120 + 1.5 × $110 = $285 $600 + 3.5 × $190 = $1,265 |
Costs are generic for this code; parts and labor on some Chevrolet models may run higher.
Watch a repair video
How to Fix a Random Engine Misfire in Your Car (Code P0300) (Scotty Kilmer). Third-party video, loads from YouTube (privacy-enhanced mode) only when you press play. Procedures vary by vehicle. Search YouTube for “P0300 Chevrolet fix” videos.
Repair manuals
Step-by-step service manuals for Chevrolet with torque specs and wiring diagrams:
Haynes manuals for Chevrolet Chilton manuals
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Check Chevrolet recalls
Enter your VIN at the NHTSA recall lookup before paying for repairs.
FAQ
Is my Chevy misfire a lifter?
Possibly if you hear ticking and the misfire stays on AFM cylinders after swapping plugs and coils.
Read the full P0300 guide or more Chevrolet check engine notes.