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P0300: Random/Multiple Cylinder Misfire Detected

HighPowertrainDIY: Advanced

Can you still drive? Not recommended. A flashing check engine light means the catalytic converter could be damaged. Reduce driving and get it fixed immediately.

What Does P0300 Mean?

Code P0300 indicates that the engine control module has detected misfires occurring in multiple cylinders at random. Unlike cylinder-specific misfire codes, P0300 points to a problem that affects the entire engine rather than a single cylinder, such as a vacuum leak, fuel delivery issue, or ignition system fault.

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Common Causes

  • Worn spark plugs or ignition coils
  • Vacuum leak
  • Low fuel pressure
  • Clogged fuel injectors
  • Failed head gasket
  • Worn or stretched timing chain/belt

Symptoms

  • Check engine light flashing
  • Rough idle
  • Hesitation or stumbling during acceleration
  • Reduced power
  • Increased exhaust emissions

Diagnostic Steps

  1. 1Read freeze frame data to identify conditions during misfire
  2. 2Check for vacuum leaks using smoke test
  3. 3Inspect spark plugs and ignition coils
  4. 4Test fuel pressure at the fuel rail
  5. 5Perform compression test on all cylinders
  6. 6Check for intake manifold gasket leaks

Recommended Parts & Tools

Estimated Repair Cost

TypeEstimated Cost
Total Repair Cost Range$100 - $2500
Parts Only (DIY)$50 - $200
Labor (1-3 hrs @ $100/hr)$100 - $300

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Get a detailed AI diagnosis for code P0300 specific to your vehicle. Includes step-by-step repair instructions, exact parts needed, and a cost breakdown tailored to your make and model.

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Commonly Affected Vehicles

Ford F-150Chevrolet SilveradoDodge Ram 1500Toyota CamryHonda Civic

Related Recalls

1 Active Recall 2026 Ford F-150

The following NHTSA safety recalls have been issued for this vehicle. Contact your dealer to check if your vehicle is affected.

Campaign #26V10400020/02/2026

ELECTRICAL SYSTEM: INTEGRATED TRAILER BRAKE CONTROL

Ford Motor Company (Ford) is recalling certain 2021-2026 F-150, 2022-2026 F-250 SD, F-350 SD, F-450 SD, F-550 SD, Maverick, 2024-2026 Ranger, 2023-2026 F-600 SD, 2022-2027 Lincoln Navigator, Expedition, and 2026 E-Transit vehicles. When towing a trailer, the integrated trailer module (ITRM) may lose communication with the vehicle, possibly causing a loss of brake and turn signal lights, or a loss of brake function. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 108, " Lamps, Reflective Devices, and Associated Equipment."

Remedy: The integrated trailer module software will be updated by a dealer, or through an over-the-air (OTA) update, free of charge. Owner notification letters are expected to be mailed March 17, 2026. Owners may contact Ford customer service at 1-866-436-7332. Ford's number for this recall is 26C10. Vehicle Identification Numbers (VINs) involved in this recall will be searchable on NHTSA.gov beginning March 17, 2026.

Data provided by the National Highway Traffic Safety Administration (NHTSA).

Frequently Asked Questions

What does a random misfire mean?

A random misfire means the engine is misfiring across multiple cylinders rather than just one, pointing to a systemic issue like fuel delivery or vacuum leak.

Can bad gas cause P0300?

Yes, contaminated or low-quality fuel is a common cause of random misfires. Try running a tank of premium fuel with fuel injector cleaner.

Is P0300 expensive to fix?

It depends on the cause. Spark plugs are inexpensive, but a failed head gasket or fuel pump can cost over $1,000.

Community Fix Reports

Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.

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