P0300- Random Misfire Detected

March 28, 2019MechVibesblog

P0300- Random misfire detected. This is a generic diagnostic trouble code(DTC) which means vehicle is misfiring and needs urgent attention in resolving the issue at hand.

In this case vehicle will hardly perform well, stumbles, loss of power and regain back to its normal condition.

There will also be vibrations in engine and steering which is also a sign of misfiring.

This also means cylinders aren’t firing according to it orders.

This problem can easily destroy the catalytic converter. Much attention is required if vehicle start to encounter such issues. I recommend catalytic converter cleaner, it helps reduce exhaust emissions and fuel consumption. Ideal if your car has failed its MOT test due to high emissions.

It mainly applied to all makes and models of vehicles.

How To Detect If Vehicle Is Misfiring

  • Engine begins to produce intended results.
  • Difficult start.
  • Vehicle will hardly move.

Diagnose Black Exhaust Smoke

Major Causes of P0300 Random Misfire

  • Bad or dead plugs.
  • Stuck or damaged injectors and regulators.
  • Stuck EGR(Exhaust Gas Recirculation) valve.
  • Air or vacuum leak.
  • Dirty or clogged throttle.
  • Bad Ignition coils
  • Electrical wiring or short to circuit

AFS (Adaptive Front-Lightning System)

Solutions to P0300 Random Misfiring

Anytime you derived such codes (P0300 Random misfire detected), the first thing to check out is your Mass Air-Flow (MAF) sensor. Check if is connected properly, when they lose contact, vehicle hardly run well, deriving such codes.

Also, you can check for bad coils, check if wires and sockets are connected properly. You can go ahead by taking each socket from the coils to see how engine sounds or perform.

Performing ignition coil test can be a good step in checking for bad coils.

Go ahead and check if plugs are damaged. This can be done by taking each plug out to check if they are firing well.

Furthermore, check for stuck or faulty injectors. Kindly perform pulse test on injectors, sometimes there may be a drop in voltage.

You can take off set of injectors with socket on each, run the engine and notice how each injector is spraying. This is also a good step when diagnosing for misfiring issues.

Finally, you can run an ultimate circuit test on the EGR valve to confirm if EGR is really opening and closing at their desired state.

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