Ignition Systems ControlOBD2 Codes

P0302 – Meaning, Causes, Symptoms, & Fixes

po302 cylinder 2 misfire detected

What Does Code P0302 Mean?

  • P0302 definition: Cylinder 2 misfire detected.
  • Issue Severity: SEVERE – Stop driving immediately
  • Repair Urgency: Fix this code immediately (same-day if possible) to avoid ignition failure, catalytic converter damage, and dangerous conditions
  • Diagnosis: A multiple misfire can be caused by anything from faulty spark plugs to low engine compression. Because there are so many variables that could cause a misfire, the best cost savings is to take your car into a shop to have it diagnosed as quickly and accurately as possible.

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Your vehicle moves when gasoline is burned and power is generated inside a chamber known as the cylinder. Most engines have a 4, 6, or 8-cylinder engine, where more cylinders typically mean more power. Power is generated by pistons that move up and down while fuel is ignited at very specific times. A misfire typically occurs when the timing of this ignition is off.  P0302 indicates that cylinder #2 is experiencing misfires. 

P0302 Causes

Misfires can be caused by many reasons from a faulty ignition system, fuel system, or internal engine failure. The most common reason for this to happen is faulty or worn-out spark plug coil packs, especially if it’s been a while since you had a tune-up.

  • Faulty or worn spark plugs and/or spark plug wires
  • Ignition issues, including failing or damaged ignition coils 
  • Distributor failure 
  • Faulty fuel injector
  • Vacuum leak
  • Low fuel pressure
  • Camshaft and/or crankshaft sensor defective
  • Engine timing off
  • Leaking head gasket
  • Low engine compression
  • Poor quality fuel that is old or contaminated

P0302 Symptoms

  • Check Engine Light is on or flashing
  • Engine runs rough, hesitates, or jerks when accelerating
  • Drivers may not notice any adverse conditions when driving
  • In some cases, drivers may experience decreased fuel economy, fuel smell from exhaust, rough idling, or lack of power from the engine
  • Commonly associated with error codes: P0300, P0301, P0303, P0304, P0305, P0306, P0307, P0308

How Do I Fix Code P0302?

With a misfire fault, the first step is to get it diagnosed to figure out what is causing the engine to misfire. 

If your vehicle is misfiring and you’re not comfortable diagnosing this issue at home, we recommend finding a RepairPal certified shop nearby to pinpoint the problem and give an accurate estimate for repairs. 

These shops can not only help you figure out what’s going wrong before you waste time and money on the wrong parts, but they also offer a minimum 12-month, 12,000-mile warranty and stand behind all their estimates with guaranteed fair pricing.

Right shop, right price

We've partnered with RepairPal to recommend certified and trustworthy shops in your local area. 

  • Upfront cost estimates
  • Minimum 12-month, 12,000-mile warranty
  • Fair price guarantee

How Much Does It Cost to Fix Code P0302?

P0302 can be caused by anything from old spark plugs to vacuum leaks to poor engine compression. It’s impossible to give an accurate estimate without properly diagnosing the issue first. 

If you take your car to a shop for diagnosis, most shops will start with an hour of “diag time” (the time spent in labor diagnosing your specific issue). Depending on the shop’s labor rate, this typically costs somewhere between $75-$150. Many, if not most, shops will apply this diagnosis fee to any required repairs if you have them perform the repairs for you. From there, a shop will be able to give you an accurate estimate for repairs to fix your P0302 code.

Possible Repair Costs for P0302

Once properly diagnosed, P0302 may require one or more of the following repairs to resolve the underlying issue. These prices are based on national averages and include parts and labor. Your cost may differ depending on your location and type of vehicle.

  • Spark plugs: $66-$250
  • Ignition Coils: $230-$640 (some cars require Intake manifold removal)
  • Spark plug wires: $180-$240
  • Fuel injectors: $1500-$1900
  • Vacuum leak: $100-$200
  • Fuel pump: $1300-$1700
  • Fuel pressure regulator: $200-$400

DIY Steps to Diagnose Code P0302

Engine code P0302 could be caused by a number of things, including faulty spark plugs, faulty ignition system, distributor failure, and more. If you’d like to try to fix code P0302 at home without throwing money at parts, you’ll want to follow the steps below for proper diagnosis. Keep in mind this is an intermediate-level diagnosis and repair and not recommended for beginners. Diagnosis requires more specialized equipment beyond what the FIXD Sensor can provide and it can be a time and labor-intensive process for inexperienced DIYers.

DIY difficulty level: Intermediate

This repair requires mechanical knowledge and is not recommended for beginners.

Tools/parts needed (our top picks from Amazon):

STEP 1: USE FIXD TO ENSURE NO OTHER ENGINE CODES ARE PRESENT.

Use FIXD to scan your vehicle to verify P0302 is the only code present. If other codes are present, they must be addressed first.

STEP 2: CHECK FOR LOOSE CONNECTORS OR DAMAGED WIRING AT THE IGNITION COILS. 

Look for loose engine ground wires as well. These can cause random misfire conditions. Tighten or connect where necessary.

STEP 3: CHECK THE CONDITION OF YOUR SPARK PLUGS AND SPARK PLUG WIRES.

Worn and old spark plug wires are common causes of random misfires. Replace spark plugs and wires if needed and recheck for misfires. 

> How to replace spark plugs in 4 easy steps

> How to identify a fouled spark plug

> How to test spark plug wires

> How to gap spark plugs

STEP 4: CHECK TO ENSURE YOUR ENGINE IS GETTING THE PROPER AMOUNT OF FUEL.

If you have determined that your ignition system is operating correctly, there may be a problem within your fuel system that is causing the random misfires. The following should be checked to ensure the engine is getting the proper amount of fuel.

  • Check fuel pressure: Low fuel pressure can cause intermittent misfires on multiple cylinders. When the pressure is below the specification, the engine does not receive the proper amount of fuel and will start to lean misfire. The fuel pump or fuel pressure regulator could be the source of the low fuel pressure.

> How to check fuel pressure

  • Check fuel injectors: Make sure the fuel injectors are functioning properly and activating. Random misfires can be a sign of faulty or clogged fuel injectors that need to be replaced. Also, check that the fuel injector wiring is not damaged and is connected properly.

> How to check fuel injectors by ear

> How to check fuel injectors with a digital multimeter

STEP 5: PERFORM ENGINE COMPRESSION AND LEAKDOWN TEST

If the ignition system and fuel system checks out, you may want to perform an engine compression test and leakdown test to see if there are any mechanical problems causing your misfire. 

Common mechanical problems that can cause misfires:

  • Leaking Head Gasket
  • Broken valve spring
  • Broken piston ring
  • Worn valve guides
  • Burned valve
  • Timing chain or belt skipped tooth and engine is off time.

Common P0302 diagnosis mistakes

Loose fitting electrical connectors and broken or disconnected vacuum hoses are often overlooked. Oxygen sensor(s) are another common misdiagnosis for P0302.

Still Need Help Fixing Code P0302?

If you’ve followed the steps above and are still experiencing misfires or check engine code P0302, please contact the FIXD Mechanic Hotline if you’re a FIXD Premium subscriber or find a RepairPal certified shop near you to get the right repairs at a fair price.

Justin-Hughes

Recovering autocross and track day enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally car.

Justin Hughes
Recovering autocross and track day enthusiast. Once turned a VW Jetta into a pickup truck. Lives in a van down by the river. Dream car: 2001 Subaru WRC rally car.

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    35 Comments

    1. You missed water in fuel/bad fuel.
      All cylinders were tagged as misfiring and stopped when the tank was refilled.
      I will be using Sea Foam on my next fill up.
      By the way. I could not clear these codes with FIXD.

      1. Hi Ric,

        Thank you for the tip! You will need the FIXD sensor and the mobile phone application in order to clear the Check Engine Light in your vehicle. If the problem with your vehicle persists, the Check Engine Light could keep setting codes.

        Thank you,
        The FIXD Team

        1. I am also unable to clear the code. The app just tells me it’s communicating and then redisplays the code. I believe I had a temporary problem. Engine ran rough for a few minutes but has been smooth ever since. I want to reset the code to see if the problem comes back.

          1. I am also unable to clear the code as well,its giving me”pol58-02 senor circuit high voltage”also “po335 pending crankshaft position sensor .A.;(3)po302 cylinder 2 misfire detected,how may I go about this

            1. I have a po302 and po305 misfire with sestem lean thats a blown head gasget right

        2. How to clear the code with the app.

          1. Hi Pierre, once you scan your vehicle with the FIXD App, you’ll be able to see all the information about your problem written in plain English and you’ll also have the ability to clear your light.

    2. Hi I have a 2000 Lincoln town car I recently had to replace the intake and since the my car has not ran correctly it keeps throwing p0300, p0301, p0302, p1450 codes and I have replaced fuel injectors, spark plugs and nothing is working…. could the purge valve be the reason these codes keep coming back

      1. This was very informative! Now’s I can do some things without asking my son. I love my independence.

      2. I replied to this, but it got stuck further down about a 2014 Dodge Charger. Sorry, but it was a lot of typing and I ain’t doing it again. This site is confusing and difficult to negotiate. Please scroll through the other questions on this thread to find it. From the same person (me).?

    3. I swapped plug wires, coil packs and checked the plugs, wiring etc. I recently replaced vacuum hoses this past summer but they were all connected. I realized that I had put gas in at a station I rarely use and had driven just enough to have the check engine light come on. I used iso heat first, to absorb the water. Then I drained the gas tank and added 5 gallons of fresh gas with seafoam added. My car started up and all symptoms gone. Cleared the code. Fixd was definitely handy. The last symptom is bad fuel.

    4. Try seafoam motor treatment fixed my 302 misfire

      1. Out of curiosity, what kind of car do you have? I have a charger that will not shake this code off, changed everything but still there

        1. I have a 2014 dodge charger and the 302 code keeps reappearing also. Plugs and wires have been changed. This code only started happening since they did recalls this year.

      2. Was your car vibrating and slighly jerking , seeming like its about to backfire before the seafoam?

    5. Rick. I have a Pontiac Sunfire and the #3 spark is misfiring. I have changed all the spark plugs and the boots, but it continue to say misfire #3. Is there something that I can do to fix this problem?

      1. Running fine
        Flashing check engine light
        Misfire #2
        Loss of power/ rough idle
        Starts: run only with rpms revved up
        *(WILL NOT ITLE)

        1. Try cleaning out your idle air and throttle body. Check it all off the list, fuel fire and air yeah?

    6. The problem with this code on my 2006 Pontiac Vibe was a bad ignition coil.
      I replaced the coil for $90 . The code is gone and the Vibe runs smooth again. Thanks for the help.

    7. This was very informative! Now’s i can do sooner things without asking my son. I love my independence.

      1. I have a dodge 2014 charger and my ABS light and check engine light are both on. They thought it was because of the spark plugs and etc (cylinder misfire), but they called back and said that it has something to do with my head gasket. The maintenance will be around $2,000 including labor. Is there any other possible things that could be wrong?

        1. Tim [with Lincoln Town Car giving misfire codes on many cylinders],
          I was on here looking up a similar code on a Hyundai Accent, but have worked on many Ford V-8s and their injection systems. It sounds like you probably have leaks at the intake ports where the intake manifold joins the cylinder heads. This will cause multiple random misfires on many or all cylinders as it not only corrupts the air/fuel mixture but also causes the sensor data to be incorrect due to air coming in downstream from the airflow and other sensor points. This causes the ECM to lean out the mixture as it is only measuring the air passing through the MAF sensor. This also causes the air flow volume and speed in the runners and intake ports to fluctuate and be slower, further throwing off the air/fuel ratio. This then causes O2 levels in the exhaust to be off, which the ECM further tries to correct, causing even more mixture error. Getting a new intake manifold (or the original) mounted on the Windsor block V-8 with no vacuum leaks can be frustratingly difficult. You may need to pull it back off and re-mount it. I would recommend getting high quality manifold gaskets(and NOT a single gasket that pans across the lifter valley) and giving them a uniform thin coat of Permatex copper gasket maker on one side, letting that “skin over” for 2 hours or so, then coating the other side and letting them sit for 15 to 30 minutes, then lightly setting them on place on the heads. Use a couple bolts through the holes as dowel pins to locate them in the right spot. They should lightly stick. Leave them for an hour or so, then CAREFULLY lower the manifold into place. Have someone help you so you can support it and lower it in so it does not slide on the gasket surfaces and only contacts them when seated. Then start the bolts in and only torque them FINGER TIGHT. Let that set overnight, then torque the bolts in proper sequence, and use at least 5 steps of torque.[If torque is 35 ft-lbs, start at 15 for all bolts, then go through the sequence at 20 ft-lbs, then at 25 ft-lbs, then 30, then 35. This gives you a layer of additional gasket material that will not all squeeze out when you tighten the bolts. Following the tightening sequence is essential to ensure the manifold is not warped or lower on one side, causing incorrect seating angle. This is generally a good method for putting an intake on ANY V-block engine, but the Ford Windsor, big block Chrysler, and some GM V-6 engines are notorious for being difficult to get a vacuum leak-free intake manifold installation achieved the first time out. Good Luck! -Brian Smith, Bradenton Florida. ?

    8. changed all spark plugs and coil engine light still comes on with code p0302

      1. I just repaired the P0302 trouble in my 04 Trail Blazer today. It was the ignition coil, $53. But there could be a very short list of other things that cause that error code. Apparently the code shows up when all of the fuel is not igniting. Plug, coil, wire are the first three main possibilities. But vacuum hose breaks and lose connections can also cause that same code.

        If the engine is not running real rough—seems to run normal, it’s not a misfiring cylinder. A missing cylinder in a small or large engine is a huge part of the balance and power, so the engine runs noticeably rough at all speeds except down hill. 🙂

    9. changed all spark plugs and coil engine light come back on with code P0302

    10. I have a 2007 Chrysler 300 touring. My engine light keeps coming on, had it into mechanics and cannot resolve a P0300 random cylinder misfire. I was looking to purchasing an older truck and the seller informed me that “I should check my tail lights – TRUST ME”. Well it does turn out that the Brake Lights do not work. All turn signals, hazard warning lights, and parking lights do work and I suspect that my brake switch is bad. I have checked for voltages at the reverse light (it’s there w/ approx. 11.7 vdc, parking light voltage is there w/ approx. 11.8vdc) but no voltages when brake pedal is depressed. Lights are good and no shorts but only an open where supposed to be. Anyone know ANY relationship with brake lights and engine/P0300 code on 2007 Chrysler 300 touring. Has about 181k miles and original owners of it.

    11. I replaced the plugs and coil pack in my 2014 cruze and it is still misfiring and throwing the misfire on cylinder 2 code.

    12. When I checked the P302 code on my Chevy Colorado 2006, I discovered that my ignition coil female wire connector doesn’t stay locked to the male wire connector. It was a low budget ignition coil.

    13. Wifely gave me a FIXD for Christmas. The CEL came on in Mini Cooper S, engine misfire on no.2, so I plugged in the FIXD, had a P0302 code. I pulled all the plugs, no.2 was black and had lots of carbon deposit. Other three plugs were light grey like they should be. Already had a set of new plugs as it was time to change so I popped in new plugs. Still had a misfire so I followed the T/S tips and found a bad coil. Ordered the four pack of oem coils from RockAuto, popped them in and she ran smooth. Was then able to clear the code and took it on a test drive. Thank you FIXD.

    14. My ECU is tuned, so the fuel mixture is always a surprise. It pops up on my in SyncUP. I check my codes with my scanner and clear them. The price of running a tuner, doesn’t bother me because my tune gave me an extra 125lbs of torque. Living in the fast lane. ?

    15. How do I determine which is cylinder 2?

    16. Hi there, can you take a look at my troubleshooting videos on youtube for a 2008 dodge nitro 3.7L i`m at the end of my rope please help! Thanks.

      https://www.youtube.com/watch?v=prOIcPmAIZU

    17. I have a P0302 error code on my 2012 GMC Sahara, 6.0L engine. I got this by rocking the van
      back and fourth to get unstuck from the snow. I will change the #2 cylinder spark plug when
      the weather worms up. This van has only 001400 miles on it. The van was only used to and from
      gigs. Too bad. I hate to have to get rid of this vehicle. I wish I purchased a Ford instead.

    18. Hey I have 2008 Ford Explorer xlt 4.0l v6
      I changed. Spark plugs. Wires. Coil pack.
      Injectors all 6. Catalytic converters. I did the compresión test. And is 150ps… and. Still misfire
      In cylinder #2. Any idea plz. Let me know

      1. pull valve cover possible cam follower

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