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AutoCodes – Infiniti – P0301 Infiniti

P0301 Infiniti Code - Number 1 Cylinder Misfire Detected

Quick Answer

When a misfire occurs, engine speed will fluctuate. Common causes include Faulty Spark Plug #1, Clogged or faulty Fuel Injector #1, Faulty Ignition Coil #1. 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
P0301 Infiniti indicates Number 1 Cylinder Misfire Detected.
Common causes
Common causes include Faulty Spark Plug #1, Clogged or faulty Fuel Injector #1, Faulty Ignition Coil #1.
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.
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Code Popularity 35,992
How popular is this code, among other codes? Low
What is this?
Table of contents Created and updated by William Orellana on Jul 21, 2022
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Code P0301 Infiniti Description

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. The Diagnostic Trouble Code (DTC) will be set when the Engine Control Module monitors the crankshaft speed and has detected that engine cylinder #1 is misfiring.
OBDII Code P0301 Infiniti - Number 1 Cylinder Misfire Detected - AutoCodes.com
P0301 Infiniti Code - Number 1 Cylinder Misfire Detected
What does this mean?

What are the Possible Causes of the DTC P0301 Infiniti?

  • Faulty Spark Plug #1
  • Clogged or faulty Fuel Injector #1
  • Faulty Ignition Coil #1
  • Fuel Injector #1 harness is open or shorted
  • Fuel Injector #1 circuit poor electrical connection
  • Ignition Coil #1 harness is open or shorted
  • Ignition Coil #1 circuit poor electrical connection
  • Insufficient cylinder 1 compression
  • Incorrect fuel pressure
  • Intake air leak

How to Fix the DTC P0301 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.

What does this mean?

Code Tech Notes

The P0301 code means that cylinder #1 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 #1. If the problem persists more tests need to be done to diagnose the problem. See "Possible Causes" for the most common problems.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0301 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 P0301 Infiniti code?

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Information for Specific Infiniti Models

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0301 Infiniti Code

No Frequently Asked Questions about P0301 Infiniti Code found.

Discuss the causes and fixes for P0301 Infiniti OBDII Code

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  • My '04 G35 Coupe showed a P0301 code at 58,400 mi. It was experiencing rough idle but fine at speed.
    New plugs cured the problem.

    Reply to Comment

  • Thanks for the information!!!

    Reply to Comment

  • Ok so I changed the valve cover gaskets, intake gaskets, thermostat, fuel injectors, coil packs and spark plugs, and now I have a misfire on cylinder so I switched around the coil packs and plugs and nothing changes... Any ideas would be great... Thanks in advance... I have a 1998 Infiniti i30t 3.0 5 speed

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  • If you have a new spark plug and ignition coil, and still getting the P0301 then you may have to replace the fuel injector. Faulty fuel injector on the I30 are a common problem.

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  • Fuel injectors are all brand new and all this started right after I installed them so I switched them around too and it's always cylinder 1 misfire

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  • I apologize, didn't see that you replace the injectors as well.
    Have you notice excessive black smoke or fuel smell? The only other thing I have seen on the I30 is that the fuel injector seal gets damage or pieces of the old fuel injector seal get stuck inside. If the seals are OK, then the next step is to perform a compression test.

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  • It's using fuel like a big truck... 1/4 tank just to go across town, smoking white at the top back end of motor and allot out the tailpipe

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  • I bet the seal is damage, I have seen that problem many times. When installing the fuel injectors add some grease to the seal and press the injectors with your hand until is all the way down, do not press the fuel injector by screwing the screws.

    Reply to Comment
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