Engine-Codes.com
Engine-Codes – Generic – P0305

P0305 Code - Cylinder 5 Misfire Detected

Quick Answer

When the diagnostic code P0305 is triggered, it indicates that a misfire has been detected in cylinder 5 of the vehicle's engine. Common causes include Faulty spark plug, Failing ignition coil, Clogged fuel injector. 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
P0305 indicates Cylinder 5 Misfire Detected.
Common causes
Common causes include Faulty spark plug, Failing ignition coil, Clogged fuel injector.
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.
What is this?
Table of contents Created and updated by William Orellana on Aug 19, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0305 Description

When the diagnostic code P0305 is triggered, it indicates that a misfire has been detected in cylinder 5 of the vehicle's engine. This means that the cylinder is not firing properly, which can lead to a number of issues with the vehicle's performance. A misfire can cause a rough idle, lack of power, decreased fuel efficiency, and potentially even engine damage if left unresolved.

OBDII Code P0305 - Cylinder 5 Misfire Detected
P0305 Code - Cylinder 5 Misfire Detected

Common Causes of P0305

  1. Faulty spark plug
  2. Failing ignition coil
  3. Clogged fuel injector
  4. Vacuum leak
  5. Low compression in cylinder 5

Symptoms of P0305

  1. Rough idle
  2. Loss of power
  3. Engine vibration
  4. Decreased fuel efficiency
  5. Engine misfires or hesitation

How to Fix P0305

  1. Perform a visual inspection of the spark plug, ignition coil, and fuel injector in cylinder 5 to check for any signs of damage or wear.
  2. Test the ignition coil with a multimeter to ensure it is functioning properly.
  3. Clean or replace the fuel injector if it is clogged or malfunctioning.
  4. Check for vacuum leaks in the intake manifold or vacuum lines and repair as needed.
  5. Perform a compression test on cylinder 5 to check for any internal engine issues causing the misfire.

Cost to Fix P0305

The cost of repairing a cylinder 5 misfire can vary depending on the specific cause of the issue. In general, replacing a spark plug or ignition coil may cost between $50 to $200, while cleaning or replacing a fuel injector can range from $100 to $500. A compression test or vacuum leak repair may cost between $100 to $300. Labor costs can add to the overall expense, with rates typically ranging from $80 to $150 per hour. It is advisable to consult with a trusted auto repair shop for a more accurate estimate based on the vehicle make and model.

What does this mean?

Tech Notes for P0305

The P0305 code means that cylinder 5 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 5. If the problem persists more tests need to be done to diagnose the problem, see "Possible Causes".









User Submitted Video

Need more information about the P0305 code?

Need more information on how to fix the P0305 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0305 code diagnosed by a professional: Find a repair shop in your area

Code P0305 Information for Specific Makes

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 P0305 Code

No Frequently Asked Questions about P0305 Code found.

Discuss the causes and fixes for P0305 OBDII Code

Submit a New Comment

  • Can p0305 be causing p0141 p0138 and p0171? Also the bank one sensor 2 oxygen sensor has a few wires that are exposed due to rubbing

    Reply to Comment

  • What make, model and year is your vehicle? A cylinder misfire problem could cause O2 sensor codes.

    Reply to Comment

  • I have a 1998 GMC sierra 1500, 5.7L vortec v8. It is misfiring on cylinder 5 and I have replace the spark plugs, distributor cap and rotor and also have spark going to the cylinder. I do not think that it is the fuel injector as it also provides fuel to other cylinders and they are running fine.

    Reply to Comment

  • If he spark plug, distributor, and injector are good, then the next step is perform a compression test. Unfortunately there is nothing else to do, also make sure there are no air intake leaks.

    Reply to Comment

  • Hi everyone
    today this code occur in my car Hyundai Azera v6 3.8L
    it happen when I accelerate in highway the check engine is turn on and engine become weak and vibrate then I return home to read the code by my laptop while the car running and it is p0305
    I turn off the car then turn it on again the engine run normally so I reset the ECU and drive my car every thing return normal
    I think some dirt in the fuel injector make this code

    Reply to Comment

  • Yes, actually there are many things that could cause the code (spark plugs, ignition coil, etc), but dirty fuel injector is probably one of the most common one.

    Reply to Comment

  • Thank you OBDIITech for your responding I like to add another cause of (misfire) I have read it in Engine repair book :
    - According to one Auto Engine Rebuilders Association (AERA) bulletin, incorrect valve spring tension can result in a rough idle that is only apparent on initial cold startup. OBD II engine computer systems sometimes sense this misfire and cause the malfunction indicator lamp (MIL) on the dash to illuminate.
    book name:
    (AUTOMOTIVE ENGINES DIAGNOSIS, REPAIR AND REBUILDING 6 T H E D I T I O N)
    many thanks

    Reply to Comment

  • Okay. I have a simple question I can't get a straight answer for anywhere.
    Let it be known I am a total novice at car repair and I am aware of this. I can change a car battery, replace brake pads, etc and I am mechanically inclined but that's the extent of it.
    I need a 100% accurate answer to the location of the 5th cylander location on a 2004 Toyota Highlander (v6, 3.3 liter)
    I have deducted that I need to replace the sparkplug and coil for the 5th cylinder. Manual is no help either.I have found diagrams showing the 5th cylinder in the rear driver side location but others show it in the front driver side. Any one who has the answer has my everlasting appreciation.

    Reply to Comment