OBD2 Codes

Ford P0300 – Meaning, Causes, Symptoms & Fixes

P0300 Random/Multiple Cylinder Misfire Detected

What Does Ford Code P0300 Mean?

  • P0300 definition: Random, Multiple Misfire Detected
  • Issue Severity: SEVERE – Stop driving immediately
  • Repair Urgency: Fix this code immediately (same-day if possible) to avoid ignition failure, catalytic converter damage, and dangerous conditions
  • Diagnosis: A multiple misfire can be caused by anything from faulty spark plugs to low engine compression. Because there are so many variables that could cause a misfire, the best cost savings is to take your car into a shop to have it diagnosed as quickly and accurately as possible.

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Your vehicle moves when gasoline is burned and power is generated inside a chamber known as the cylinder. Most engines have a 4, 6, or 8-cylinder engine, where more cylinders typically mean more power. Power is generated by pistons that move up and down while fuel is ignited at very specific times. A misfire typically occurs when the timing of this ignition is off.  P0300 indicates that two or more cylinders are experiencing misfires

Ford P0300 Causes

Misfires can be caused by many reasons from a faulty ignition system, fuel system, or internal engine failure. The most common reason for this to happen is faulty or worn-out spark plug coil packs, especially if it’s been a while since you had a tune-up.

  • Faulty or worn spark plugs and/or spark plug wires
  • Ignition issues, including failing or damaged ignition coils 
  • Distributor failure 
  • Faulty fuel injector
  • Vacuum leak
  • Low fuel pressure
  • Camshaft and/or crankshaft sensor defective
  • Engine timing off
  • Leaking head gasket
  • Low engine compression
  • Poor quality fuel that is old or contaminated

Ford P0300 symptoms

  • Check Engine Light is on
  • Check Engine Light flashing
  • Engine runs rough and shaking
  • Lack of power from the engine
  • Fuel smell from the exhaust
  • Hesitations/Jerking when accelerating

How do I fix Ford code P0300?

The most common reason for engine code P0300 is faulty or worn spark plugs and/or spark plug wires or coils.

>>> RELATEDHow to replace spark plugs

>>> RELATEDAverage cost to replace spark plugs

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  • Upfront cost estimates
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Other common Ford P0300 causes

  • Distributor failure 
  • Faulty fuel injector 
  • Vacuum leak
  • Low fuel pressure
  • Camshaft sensor defective
  • Crankshaft sensor defective
  • Engine timing off
  • Leaking head gasket
  • Low engine compression
  • Poor quality fuel

How much does it cost to fix Ford P0300?

For error code P0300, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair. These prices are based on national averages. Your cost may differ depending on your location. Click on the links to learn more about each repair.

  • Spark plugs cost: $66-$250 (depending on if you take it to the shop or do it yourself)
  • Ignition Coils: $230-$640 (some cars require Intake manifold removal)
  • Spark plug wires: $180-$240
  • Fuel injectors: $1500-$1900
  • Vacuum leak: $100-$200
  • Fuel pump: $1300-$1700
  • Fuel pressure regulator: $200-$400

Can I fix Ford code P0300 myself?

Ford code P0300 is considered an intermediate level diagnosis and repair for most DIYers. Watch the video below and follow the steps to diagnose and fix this fault code or schedule repairs so you can get back on the road.

Ford code P0300 diagnosis steps

Ford code P0300 common diagnosis mistakes

Loose fitting electrical connectors and broken or disconnected vacuum hoses are often overlooked.

Tools Needed to Diagnose:

  • Tools You May Already Have:
  • Tools You May Need (FIXD’s Top Picks From Amazon):
    • FIXD
    • Digital multimeter
    • 5/8in. Spark Plug Socket
    • Ratchet, sockets, and extensions
    • Fuel pressure gauge
    • Compression tester
    • Leakdown tester
    • Spark plugs
    • Spark plug wires

How to diagnose Ford code P0300

  1. Use FIXD to scan your Ford to verify P0300 is the only code present. If other codes are present, they must be addressed first.
  2. Check for loose connectors at the ignition coils or for damaged wiring. Look for loose engine ground wires as well. These can cause random misfire conditions. Tighten or connect where necessary.
  3. Check the condition of your spark plugs and spark plug wires. Worn and old spark plug wires are common causes of random misfires. Replace spark plugs and wires if needed and recheck for misfires.
  4. If you have determined that your ignition system is operating correctly, there may be a problem within your fuel system that is causing the random misfires. The following should be checked to ensure the engine is getting the proper amount of fuel:
    • Check fuel pressure. Low fuel pressure can cause intermittent misfires on multiple cylinders. When the pressure is below the specification, the engine does not receive the proper amount of fuel and will start to lean misfire. The fuel pump or fuel pressure regulator could be the source of the low fuel pressure.
    • Check that the fuel injectors are functioning properly and activating. Random misfires can be a sign of faulty or clogged fuel injectors that need to be replaced. Also check that the fuel injector wiring is not damaged and is connected properly.
  5. If the ignition system and fuel system checks out you may want to perform an engine compression test and leakdown test to see if there are any mechanical problems causing your misfire. Some common mechanical problems that cause misfire can be:
    • Broken valve spring
    • Broken piston ring
    • Worn valve guides
    • Burned valve
    • Timing chain or belt skipped tooth and engine is off time.

Still need help fixing Ford code P0300?

If you’ve followed the steps above and are still experiencing misfires or check engine code P0300, please contact the FIXD Mechanic Hotline if you’re a FIXD Premium subscriber or find a RepairPal certified shop near you to get the right repairs at a fair price.

Justin-Hughes

Recovering autocross and track day enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally car.

Justin Hughes
Recovering autocross and track day enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally car.

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    5 Comments

    1. Thank you. most accurate and helpfull my spark plugs were worn out and should have ben replaced a long time ago. I got the van like this check engine light on. Replaced the worn plugs and now perfect. 96 areostar xlt 3.0 liter vulcan engine with 267000 miles. Runs awesome now.

      1. So glad to hear it, Jason! We are happy to provide a tool that helps people learn more about their car and fix it themselves. Happy and safe driving!

    2. Hi I got Ford Figo 2016 tdci 1.4 won’t start P0300 and report cylinder 12 contribution range fault what’s mining of I did open tepit cover air Hou cylinder I fine metal fine what I can do for reper plz thank you

      1. Fix

    3. I’m getting a code P0300, p0301 and p0305. I read everything and thank you. But I know nothing about engines. I’ll have to get someone to work on it. Just don’t want to be Bamboozled on price. I’m disabled and have little money saved up. About what kind of price am I looking at? michaelslusher@gmail.com or text 256-810-1311
      Thank you

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