Select your vehicles year, make, and model and the repair service you need.
Get a free quote, book an appointment, and speak to a specialist – all online!
Pick a time that works best for you and our mobile mechanics will bring the shop to you.
We perform over 600 repair and maintenance services including oil changes, brakes, diagnostics, belts and hoses, and more. The best part? We come to you with all the necessary tools and parts.
Code P0300 is defined as “Random or Multiple Cylinder Misfire Detected.”
This Diagnostic Trouble Code (DTC) indicates that your car’s computer has caught a random misfire, multiple cylinder misfire, or both.
There’s a high chance you’ll find another OBD-II fault code. P0301 to P0312 are related trouble codes — and along with P0300, as they all suggest an engine misfire.
Your car will typically have 4-6 cylinders, where each cylinder will fire a spark plug in a smooth and steady manner.
Using the flammable fuel-air mixture, the spark plug fires a spark to set fire to the fuel. As a result, the fuel releases energy powering the crankshaft — which needs to continuously turn as the car moves.
If more than one cylinder misfires, the crankshaft’s revolutions per minute (RPM) will increase or decrease. Now, if that increase or decrease or both is more than 2%, the Powertrain Control Module will capture a P0300 trouble code indicating there’s a cylinder misfire in random or multiple cylinders.
When your car stores the OBD-II code P0300, you’ll likely experience one or more of the following symptoms:
The P0300 trouble code is serious because it causes driveability problems. For example, your car may not start or idle rough. That’s why you shouldn’t delay resolving the check engine code P0300.
Also, since this fault code involves multiple cylinder misfires, it often arises with related misfire codes (from P0301-P0312, which indicate a misfire on a specific cylinder).
Moreover, misfires can demand expensive repair services, so get it diagnosed by your mechanic ASAP.
A multiple misfire can happen due to many reasons triggering the misfire code.
Here are some of the common causes:
Here’s how your mechanic will go about the diagnosis:
The cost can be anywhere between $75 to a bit over $700.
The wide range is because P0300 can be caused by anything from an old spark plug to a vacuum leak to poor engine compression. It’s impossible to find an accurate cost estimate without first diagnosing the issue correctly.
When you call a professional mechanic, they’ll charge you for the diagnosis time, labor, and repair parts if your car needs them.