Engine-Codes - Toyota - P0304 TOYOTA

P0304 TOYOTA Code - Cylinder 4 Misfire Detected

- Code Popularity: 93,742 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents

|What are the Possible Causes of the P0304 TOYOTA Code?

  • Faulty spark plug 4
  • Clogged or faulty fuel injector 4
  • Faulty ignition coil 4
  • Fuel injector 4 harness is open or shorted
  • Fuel injector 4 circuit poor electrical connection
  • Ignition coil 4 harness is open or shorted
  • Ignition coil 4 circuit poor electrical connection
  • Insufficient cylinder 4 compression
  • Incorrect fuel pressure
  • Intake air leak

|How to Fix the P0304 TOYOTA Code?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

|P0304 TOYOTA code tech notes

The P0304 code means that the cylinder 4 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 4. If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes"

|What is the cost to diagnose the P0304 TOYOTA code?

Labor: 1.0

The cost to diagnose the P0304 TOYOTA code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

|When is the P0304 TOYOTA code detected?

Engine Cylinder 4 is Misfiring.

|What are P0304 TOYOTA code possible symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Lack/loss of power
  • Hard start
  • Engine hesitation

|What Does the P0304 TOYOTA Code Mean?

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.

Cylinder 4 Misfire Detected

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