P0304 Infiniti Code - Number 4 Cylinder Misfire Detected
Quick Answer
When a misfire occurs, engine speed will fluctuate. Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0304 Infiniti indicates Number 4 Cylinder Misfire Detected.
- Common causes
- Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0304 Infiniti Description
What are the Possible Causes of the DTC P0304 Infiniti?
- 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 DTC P0304 Infiniti?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0304 Infiniti code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
Need more information about the P0304 Infiniti code?
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Information for Specific Infiniti Models
- P0304 2003 Infiniti G35 — Number 4 Cylinder Misfire Detected
- P0304 2004 Infiniti G35 — Number 4 Cylinder Misfire Detected
- P0304 2005 Infiniti G35 — Number 4 Cylinder Misfire Detected
- P0304 2006 Infiniti G35 — Number 4 Cylinder Misfire Detected
Frequently Asked Questions about P0304 Infiniti Code
What does OBD-II code P0304 mean for an Infiniti?
Code P0304 indicates a misfire in cylinder number 4, meaning the engine isn't firing properly in that specific cylinder.
What are common symptoms of a P0304 code?
Symptoms include rough engine idling, decreased fuel efficiency, difficulty starting the engine, and the Check Engine Light turning on.
What can cause a P0304 code in an Infiniti?
Common causes include a faulty spark plug, bad ignition coil, clogged fuel injector, vacuum leak, or low cylinder compression.
Can driving with a P0304 code damage my Infiniti?
Yes, driving with a misfire can cause further engine damage and harm the catalytic converter due to unburned fuel entering the exhaust system.
How do you diagnose a P0304 code in an Infiniti?
Diagnosis involves checking the spark plug, ignition coil, fuel injector, and cylinder compression, as well as inspecting for vacuum leaks or wiring issues.
What are the repair options for a P0304 code?
Repairs may include replacing the spark plug or ignition coil, cleaning or replacing the fuel injector, fixing vacuum leaks, or addressing low cylinder compression.
Can a dirty fuel injector cause a P0304 code?
Yes, a clogged or malfunctioning fuel injector can disrupt fuel delivery to cylinder 4, leading to a misfire.
How much does it cost to fix a P0304 code in an Infiniti?
The cost varies depending on the cause, but replacing a spark plug or ignition coil may cost $100-$300, while more complex repairs like resolving compression issues could be significantly higher.
Can bad fuel cause a P0304 code?
Yes, contaminated or low-quality fuel can lead to improper combustion and contribute to cylinder misfires.
Should I reset the P0304 code after repairs?
Yes, after completing repairs, use an OBD-II scanner to clear the code and ensure the issue has been resolved.
Discuss the causes and fixes for P0304 Infiniti OBDII Code
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I have a 97 q45 and changed all the plugs , diagnostic says misfire on 1. Took all back apart and changed plug again. Car seems to run well until get speed up. then it shakes somewhat... any ideas
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More than likely you have a problem with the ignition coil. You should try swapping the coil #4 with the #6. If after swapping the coil you get the P0306 code, then the problem is the coil you installed on the cylinder #6.
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hay i have a 04 Infinity FX35 with a po304 code, Ive changed the sparkplug as well as the coil. But i still get the code PO304. Ive even changed coil 2 to 4 and still get code PO304
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Although is not common, the next step is to check or change the fuel injector. If the injector check OK, the next step is to perform a compression test. The ignition coil is probably the most common problem, make sure the connector is fully connected.
When did the problem started?
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