Q: Car misifires under load, P0300 code

asked by on

My car has been idling fine. However, when the car is under load, it starts misfiring. I had the code reading of the vehicle and the P0300 error code appeared. What do you think is the matter with my car?

Hello. The P0300 code refers to a detection of a misfire in one of the cylinders. If the car idles fine and only acts up during acceleration with this code coming up, then it is usually caused by a fuel system issue. A weak fuel pump will cause low pressure and this will occur. There are other sensors that can also cause this but the pump is the most common. I usually check the fuel pressure first. If you are planning on having this repaired, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the misfiring issue more thoroughly and make any repairs that are needed.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Car misifires under load, P0300 code

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Don't understand CEL Codes.

The codes P0300 through P0306 are for misfires of random cylinders or different cylinders. The second code P1456 is for the evaporative fuel tank system having a leak somewhere in the system. Since you are getting random misfires, then I...

Q: Rough idle/Check Engine light/Cylinder # 2 misfre

Hello, thank you for writing in. The spark plugs may absolutely be the cause of your misfire. Even if only one cylinder is registering a misfire at this time, you should replace all of them at the same time. The...

Q: 2002 Jeep Liberty Limited 3.7 misfire bent spark plug tip with rough idle

I can't find any information suggesting there is a recall for your vehicle. Either way, you need to figure out what has failed in cylinder number two. Replacing all the injectors is not going to fix the problem in cylinder...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.