P0304 P0304 OBD-II: Misfire Detected in Cylinder 4
What P0304 means for you
This code indicates a misfire in a specific cylinder, which can lead to performance issues and increased emissions.
Symptoms
- Flashing Check Engine Light
- Engine running roughly
- Hesitation or jerking during acceleration
- Often, drivers may not notice any significant issues
- In some instances, performance can degrade, leading to stalling at stops or rough idling
- Possible misfires or loss of power, particularly when accelerating
- Reduced fuel efficiency
Common causes
- The engine control module (PCM) identifies that cylinder four is not adequately contributing to engine performance
- This triggers the P0304 code
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Send your ECUWhat this code means
The P0304 code signifies that the engine control module has detected a misfire in cylinder four, indicating that this cylinder is not firing as expected, which can disrupt overall engine operation.
How a workshop diagnoses it
1. Use an OBD-II scanner to confirm the P0304 code and check for any additional codes. 2. Record freeze frame data to understand the conditions under which the code was set. 3. Conduct a test drive to replicate the code-setting conditions, monitoring engine load, throttle position, RPM, and vehicle speed. 4. If available, examine the misfire counter data for cylinder four. 5. If no misfire counter is present, swap components like spark plugs or ignition coils to identify the faulty part.
Frequently asked questions
It is not advisable to continue driving with a P0304 code as it indicates a misfire, which can lead to further engine damage.
The repair costs can vary widely, typically ranging from $100 to $400, depending on the underlying issue and necessary parts.
Common symptoms include a flashing Check Engine Light, rough engine performance, and potential stalling or loss of power.
A P0304 code is caused when the PCM detects that cylinder four is not firing properly, indicating a misfire.
