P0304 KIA Code - Cylinder 4 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 KIA indicates Cylinder 4 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 KIA Description
What are the Possible Causes of the DTC P0304 KIA?
- 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 KIA?
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
There is a Factory Service Bulletin to upgrade the Powertrain Control Module (PCM) of some 2010 Model Year Forte (TD) Sedan and Koup with 2.0L engines manufactured between 3/5/09~3/17/10. This reflash has enhanced VCM (Variable Charge Motion) Actuator logic to improve a rough idle condition at start-up or a MIL ON and stored DTC P0304 set at start-up. To improve customer satisfaction Kia is requesting the completion of this Service Action on all affected 2010 Forte & Forte Koup w/2.0L engine vehicles.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0304 KIA 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.
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Frequently Asked Questions about P0304 KIA Code
1. What are the common symptoms of OBDII code P0304 in a KIA, indicating a Cylinder 4 Misfire Detected?
- Common symptoms include engine misfiring, rough idling, loss of power, and potential engine vibrations.
2. What are the typical causes of OBDII code P0304 in a KIA?
- The most common causes of this code are spark plug issues, faulty ignition coil, vacuum leaks, fuel injector problems, or low compression in cylinder 4.
3. How can I diagnose the reason behind OBDII code P0304 in my KIA?
- Diagnose by checking spark plugs, ignition coils, fuel injectors, vacuum hoses, compression levels, and performing a visual inspection for any visible damages.
4. Can a dirty or clogged fuel injector trigger OBDII code P0304 in a KIA?
- Yes, a dirty or clogged fuel injector can disrupt the air-fuel mixture in cylinder 4, leading to misfires and triggering the P0304 code.
5. Is it safe to drive my KIA with OBDII code P0304 indicating a Cylinder 4 Misfire Detected?
- It is not recommended to drive your KIA with a misfire, as it can cause damage to the catalytic converter and other components. It's best to address the issue promptly.
6. How can I repair OBDII code P0304 in my KIA at home?
- You can try DIY solutions like replacing spark plugs, ignition coils, or cleaning fuel injectors. However, for a thorough diagnosis and repair, it's advisable to seek professional help.
7. Will resetting the OBDII code P0304 in my KIA make the issue go away permanently?
- Resetting the code without addressing the underlying cause will not fix the problem permanently. It's essential to diagnose and repair the root issue to prevent the code from reoccurring.
8. Can extreme weather conditions contribute to triggering OBDII code P0304 in a KIA?
- Yes, extreme temperatures can sometimes exacerbate existing issues related to ignition components or fuel delivery, potentially leading to misfires and triggering the P0304 code.
9. How much can I expect to pay for professional repair of OBDII code P0304 in my KIA?
- The cost of repairing OBDII code P0304 can vary based on the underlying issue, but it may range from $100 to $500 or more, depending on the parts and labor required.
10. Will regularly maintaining my KIA help prevent OBDII code P0304 from occurring?
- Yes, regular maintenance such as changing spark plugs, inspecting ignition components, and ensuring proper fuel system operation can help prevent misfires and the occurrence of code P0304.
Discuss the causes and fixes for P0304 KIA OBDII Code
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Code P0304 on 2004 Kia Sedona V6 3.5L engine . Changed plugs and wires and coil short boots about a year ago and now this code came up. swapped plugs from #4 to #6 and and now the light is coming on and off intermittently. Same Cyl misfire. I'm going to Swap ignition coils today from $ to 6 and clear codes and see what happens. Any suggestions please advise . Appreciate the help.
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Swapping coils it's the best option to try to diagnose the problem. Also, I suggest to use high octane gas and if possible add some fuel additive. Dirty fuel injector can also cause the same problem.
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Code p0304 on kia Sedona 2004.ater changing the plugs,the problem has stopped
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had multiple issue with code P304 on my 2010 Kia Forte.
I brought it to a mechanic and they wanted $400 to change sparks & coils. told them no thanks.
I changed coils and it worked for about 4 months and the code tripped again. Tried fuel injector cleaner and changed spark plugs which were needed and worked until recently when I let the car sit for 1 week while I drove my SUV in the snowy conditions. Ran the car for 15 minutes, did an oil change. Started it the next let it warm up and soon as I got on the road, I'm getting intermittent engine light. (OBDII reads as P304) Light goes off if I'm coasting down a hill and no strain on the engine... any ideas? -
What is the engine size of your Forte?
There is a factory service bulletin for the Forte 2.0 with the P0304 code. The factory recommends reprogramming the Engine Control Module (ECM) to fix the problem. See "Tech Notes" above, -
If the engine is 2.0, then you should reprogram the ECM, there is Factory Service Bulletin for that problem.
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