Skip the auto shop - Our mechanics make house calls

Q: Misfire on cylinder 4; error code P0304

asked by on

I know I have a misfire on cylinder 4 (error code P0304), but I can't find the problem.

A: The misfire is caused by one or more of sev...

The misfire is caused by one or more of several possible causes: the coil, a spark plug, an injector, wiring, compression in the cylinder, or the computer for the engine. Any one of these could be the culprit and diagnosis can be made only after a thorough check of each item. I recommend you have a mechanic like one from YourMechanic inspect your vehicle’s misfiring issue to see what repairs you need moving forward.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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: How do you open the fuel door?

In order to fill your gas tank, you’ll need to open the fuel door. However, your fuel door is secured in order to prevent possible siphoning attempts. To open the fuel door, you’ll need to use the switch. Here’s how:...

Q: Hiccup while accelerating

There are a number of things that may cause the car to hesitate when accelerating such as low fuel pressure, a dirty or faulty mass air flow sensor, clogged or dirty fuel injectors, a faulty throttle position sensor or potentially...

Q: bogs down with heavy acceleration no codes all sensors read normal fuel pressure is ok.

This sounds like a very tricky problem to diagnose. Did you check the fuel pressure with the fuel pressure regulator disconnected? Perhaps there isn't enough fuel pressure at full throttle, or the fuel pressure regulator leaks and floods it out...

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...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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.