The OBD code P0304 for a Toyota indicates a misfire in cylinder 4. This affects the engine’s performance, leading to symptoms like engine light on, lack of power, hard starting, and engine hesitation.
Common causes include a faulty spark plug, ignition coil, or fuel injector in cylinder 4. While not an immediate danger, it can lead to further issues if left unresolved.
A possible fix involves inspecting and repairing the components related to cylinder 4, such as checking wiring harnesses and connectors for damage.
| Repair Importance Level | 10.0 (Out of 10) |
| Estimated Repair Time | Approximately 1.0 hour |
| Repair Difficulty Level | 10.0 (Out of 10) |
Symptoms of the Toyota p0304 OBD Code
The vehicle may experience rough idling, lack of power, and engine misfires with fault code P0304.
- With Toyota OBD code P0304, the Engine Light will be ON.
- Lack/loss of power may be experienced.
- Hard start can occur.
- Engine hesitation might be noticeable.
Causes of the Toyota p0304 OBD Code
P0304 in a Toyota indicates a misfire in cylinder 4, often triggered by ignition or fuel issues.
- P0304 can be caused by a faulty spark plug #4.
- A faulty ignition coil #4.
- Clogged or faulty fuel injector #4.
- Fuel injectors #4 harness is open or shorted.
- Fuel injectors #4 circuit poor electrical connection.
- Ignition coils #4 harness is open or shorted.
- Ignition coils #4 circuit poor electrical connection.
- Incorrect fuel pressure.
- Faulty Mass Air Flow (MAF) Sensor.
- Faulty Engine Control Module (ECM).
- Faulty Engine Coolant Temperature (ECT) Sensor.
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Fixing Toyota Error Code p0304 Step By Step
Address misfire in cylinder 4 by checking spark plugs, ignition coil, fuel injector, and compression.
- To fix a Toyota OBDII code P0304, start by reviewing the possible causes related to cylinder 4 misfire.
- Visually inspect the ignition system components such as spark plugs, ignition coils, and spark plug wires for any signs of wear or damage.
- Check the fuel injector for proper operation and ensure it is delivering fuel to the cylinder.
- Test the compression in cylinder 4 to verify the engine’s mechanical condition.
- If all components check out, consider swapping the ignition coil or fuel injector with another cylinder to see if the misfire moves.
- Finally, reset the engine control module (ECM) to clear the code and monitor the vehicle for any recurring issues.
Cost Of Fixing Toyota p0304 Fault Code
The repair for Toyota code P0304 may involve replacing a faulty ignition coil or spark plug.
The cost to diagnose and fix a Toyota OBD code P0304 typically ranges from $75 to $150 per hour for labor rates.
With an estimated repair time of 1. 0 hour, the total cost could be around $75 to $150, depending on shop rates and the complexity of the issue.
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Details of the Toyota p0304 OBD Code
Fault code P0304 indicates a misfire in cylinder 4 on a Toyota vehicle.
Code P0304 means a misfire was detected in cylinder 4 of the engine.
This code is triggered by the Engine Control Module (ECM) when it detects a deviation in crankshaft speed caused by a misfire in that specific cylinder.
The ECM monitors the engine’s crankshaft speed using data from the crankshaft position sensor and compares it to the expected values for smooth engine operation.
When a misfire occurs in cylinder 4, it causes a disruption in the crankshaft speed pattern, leading the ECM to set code P0304.
Mechanic’s Tech Notes
For Toyota code P0304, cylinder 4 misfire detected, check ignition system, fuel injector, and compression.
To diagnose and fix OBDII code P0304 on a Toyota, start by checking the ignition system components like spark plugs, ignition coils, and spark plug wires for any issues.
Use a voltmeter to test the ignition coil’s primary and secondary circuits for proper voltage and resistance.
Inspect the fuel injector for clogging or malfunction.
Perform a compression test to check the engine’s mechanical condition.
Additionally, check for vacuum leaks or intake manifold issues that could affect cylinder #4. Reset the code after addressing the root cause and monitor for recurrence.
FAQ
Common causes of OBD code P0304 in a Toyota: Faulty spark plug #4, faulty ignition coil #4, clogged/faulty fuel injector #4, or intake air leak.
Diagnose P0304 misfire in Toyota: Check spark plug, ignition coil #4, fuel injector #4, wiring harness, connectors. Look for damage, corrosion. Fix as needed.
It is not safe to continue driving with OBD code P0304 on a Toyota. Check spark plug, ignition coil, fuel injector, wiring for issues.
Wrap Up
If your Toyota is experiencing OBDII code P0304, you may notice symptoms like engine misfires, rough idling, and decreased fuel efficiency.
This code typically indicates a misfire in cylinder 4, which could be caused by faulty spark plugs, a failing ignition coil, clogged fuel injector, or low compression in that cylinder.
To address Toyota OBDII code P0304, start by checking the spark plug, ignition coil, and fuel injector in cylinder 4. Inspect the wiring harness and connectors for any damage or corrosion that could be affecting the components’ performance.
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