Cylinder 2 Misfire: How To Identify And Fix This Problem

by Conner Mckay

Engine cylinder 2 misfire reduces your engine’s power and can lead to severe complications. The P0302 OBD2 code triggers when cylinder 2 experiences misfires. Knowing which cylinder has problems is very beneficial when preparing to make repairs.

The cost of getting your engine fixed can be astronomical, and you have no idea how many of those repairs are needed just because the wrong code was set. With an OBD2 scanner tool, it’s easy to track how engine performance is changing and get ahead of potential problems before they become too expensive.

If you’re like most motorists, the last thing you want to see is a check engine light. All too often, it’s a sign of expensive repairs and vehicle downtime. But there’s no need to panic! In many cases, a check engine light indicates a minor operational issue that can be resolved quickly and easily.

You need to know that a check engine light is triggered when an engine’s control module stores a diagnostic trouble code. It can be caused by anything from a loose gas cap to a faulty sensor. But don’t worry – most of these problems are easy (and inexpensive) to fix.

So if you see that dreaded check engine light, don’t delay! Bring your car to a mechanic, or you can DIY with simple tricks that we will discuss in the further article.

So let’s dig deeper inside the article to learn about this problem and how you can diagnose it.


The spark plug isn’t firing correctly if your engine cylinder 2 is misfiring. It can cause problems, from decreased fuel economy to increased emissions. In some cases, it can even cause engine damage.

Sometimes the regarding cylinder faces incomplete combustion, which leads to this problem more often. The spark plug defect is considered the root cause of this problem is something that we will discuss later, and how you can get rid of it.

Cylinder 2 Misfire

If you notice any strange sounds or smells coming from your engine, it’s time to get it checked out. A build-up of carbon deposits often causes an engine cylinder to misfire on the spark plugs. If left untreated, this can eventually lead to severe engine damage.

Furthermore, some rare causes of this problem is suppressed compression, which is due to the high mileage of the vehicle.

P0302 Cylinder 2 Misfire Detected

As far as cars are concerned, they come in all sorts of engine configurations. Some of them are 4-cylinder, 6-cylinder, and more cylinders which come in high-performance or sports cars.

There is always a spark plug located on top of the cylinder near the camshaft in every cylinder to ignite the air-fuel mixture, leading to an engine’s combustion of fuel and air.

But sometimes, due to technical problems like a bad spark plug, and ignition timing disruptions due to various causes, lead to the check engine light blinking. That is where you should know that the crankshaft RPM is either decreased or increased by a percentage of about 10%.

If you’re a car owner, chances are you’ve come across a ‘P0302 Cylinder 2 Misfire Detected’ error before. P0302 code is one of the most common codes that mechanics deal with. It’s a simple code that indicates a misfire in one of your cylinders.

There are a few reasons why your cylinder might be misfiring. The most common reason is a problem with your spark plugs. Sometimes, debris or oil can build up on the spark plugs, causing them to misfire.

Another common reason for a P0302 code is worn-out intake valves. If your intake valves are worn out, they can’t open and close properly, which causes a misfire.

Engine Misfire Symptoms

Multiple types of symptoms show the cylinder 2 misfire indication, which is given as follows:

P0302 engine problems troubleshooting

  • First, inspect if the check engine light is flickering or blinking MIL (malfunction indicator lamp); it means you should quickly stop the engine and must check it
  • Vehicle acceleration shows an abnormality
  • The car engine does not start quickly due to poor ignition problems
  • Engine power seems to be lacking while speeding
  • Engine dead or stops during the drive
  • Fuel consumption of your car gradually increases
  • Exhaust releases an unusual smell from the engine

Misfire Causes

It’s hard to imagine what it would be like to live in constant fear of your car breaking down. Imagine the anxiety and stress it would give you if you were driving on the highway and your engine died.

Imagine how long it would take you to get your car fixed if all of your rides were at home or work! With so many worries weighing on you, it’s no surprise that people find themselves procrastinating, putting off fixing their car until it becomes a bigger problem.

What causes a cylinder to misfire is the primary concern here, so let’s move into the root cause of this problem and how some are considered severe.

Common Cylinder 2 Misfire Causes

Many conditions can cause this problem, but some could be very dangerous, except a few rare and less harmful. The list of the highlighted causes is given below:

  • Faulty ignition coil
  • Faulty fuel injectors
  • Poor #2 spark plug and wires connection
  • Severe vacuum leakage inside the engine
  • Defective fuel system including fuel injector, fuel pump, fuel filter, and fuel pump electrical relay
  • Engine piston rings problem due to wall sticking
  • Cylinder 2 misfires after spark plug change
  • Engine head gasket leakage
  • Poor quality EGR valve
  • Low compression inside the #2 engine cylinder
  • PCM malfunction
  • EGR passageways clogging

How Severe Is This

The severity level depends on how quickly you take action upon the symptom’s indication. If you don’t check the symptoms on time, it can cause severe problems like engine malfunctioning or engine parts deterioration.

Did you know that the catalytic converter is responsible for preventing harmful emissions and pollution in the air? Have you realized that it can cause severe damage if it malfunctions, as well? Catalytic converters are critical in reducing NOx and particulate emissions, but they can’t do their job if they flush out unburnt fuel.

It could be the only more severe problem that can be caused due to cylinder 2 misfires, and you should quickly fix it before it’s too late.

Don’t be alarmed if you see the P0302 code on your car’s dashboard – it doesn’t necessarily mean that your engine is in danger! This code indicates that there’s an issue with the catalytic converter.

While it’s certainly worth getting this problem fixed, it’s not as severe as other codes. So please don’t panic, and take your car to the experts to check the P0302 code and fix it.

Engine Misfire Repair

Now you know the causes of this problem, but how would you diagnose this problem? It should be the primary concern if you are traveling to another city and standing in the middle of nowhere.

The only thing you can do is diagnose it by yourself or DIY, so you might not be late for your important meeting. To perform the self-checking process, you need to know the diagnosing basics with proper precautionary measurements to some relevant engine parts to avoid any mishap.

Let’s jump into the steps of diagnosing the p0302 code that will lead you to the real problem-causing need, and how to fix a misfire is our only concern later.

There are several steps to diagnose this problem which you need to check one by one to reach the root cause.

Step 1: Check Wiring And Connections Of Ignition Coils

Start by checking the engine’s number #2 spark plug. Make sure there is no damage and that the gap spacing is proper. A spark plug or wire malfunction could be preventing the engine from firing. The only way to find out is to pull that specific component so it can be examined.

Then, check the spark plug wire for signs of damage or burning. Check the #2 coil pack for arcing or other damage if the engine is coil-on-plug designed. Finally, if applicable, evaluate the distributor cap for any possible signs of wear.

Must check any wire loose end because it can cause a gap between the engine’s ignition. Try to tighten up all the loose wires.

Cylinder 2 Misfire

You need to change the coil packs if the problem is not resolved and test by running the car; if you see any problem in the coil, you exchange it with another one and then change the coil.

During the check, if you find any of these parts in some unusual condition than a normal one, then better change it quickly; otherwise, you will face severe engine malfunctioning issues.

Step 2: Examine Spark Plugs And Wire Conditions

After checking the first central part, immediately move to the spark plug and check it with an inline spark tester. It will help you testify to the problem of whether the spark plug is working. If you see any dirt or carbon pile up around the spark plug ignition area, then better remove it and clean it properly.

You can also plug your vehicle with a diagnostic scanner for the latest and most accurate diagnosis. Diagnosing engine problems can be a long and frustrating process, but you can quickly get the job done.

Cylinder 2 Misfire

It is a plug-in for your OBD II scanner that allows you to determine if all your spark plugs are firing smoothly if there are any misfires on any cylinder, and even if there is an issue with your wire harness.

Use the multimeter to inspect the spark plug resistance, which should be between 10k – 15k ohms. If you see any wire showing higher resistance than its typical range, you should change it.

Check the wires’ conditions connected to spark plugs and see if there is any damaged wire. Change or repair the wire if you find any wire unhealthy.

Step 3: Ensure Fuel Injector Working Properly

Your car’s fuel injectors are the heart of the engine. They can cause a “P0302” code when they run out of gas. Use a multimeter by unplugging the fuel injector to investigate the terminals.

Check the fuel injection ratio is according to the given by the car manual. If it does not provide the proper mixture to the cylinder, consider changing the fuel injector.

Step 4: Bring Off A Leakdown And Engine Compression Test

A leak down and compression test are similar with few differences. The leak-down test measures the leakage or pressure loss from the engine.

To perform this test, you need to remove all the spark plugs from the engine cylinder and move the crankshaft at TDC (top dead center) to ensure all valves are closed.

After that, attach the leakage gauge to the spot where the spark plugs were located from cylinder one. About 80-90 PSI compressed air is supplied into the cylinder and check the gauge meter.

The best-condition engine will show a 5% – 10% leakage. Up to 30% of leakage is ignorable, but more than 30% shows the dire condition of the engine.

If your engine compression shows more than 30%, quickly contact a professional mechanic to repair the engine leakage problems.

Step 5: Check Other Causes Of Cylinder 2 Misfire

If you find nothing after all these tests mentioned above, consider the valvetrain problem in your engine. These problems include damaged valve springs, twisted pushrods, torn cam lobes, damaged piston rings, irregular teeth, etc.

The minimal leakage with less compression is also caused due to defective valve timing. It would help if you repaired or changed it.

The issue remains unresolved after all of these tests; you should check the PCM (powertrain control module), a rare problem. Check the PCM and try to reprogram it.

Step 6: Inspect the Air Intake and EGR Systems

Air intake is crucial for combustion. Inadequate air can starve the cylinder, leading to a misfire. First, check the air filter. A clogged or dirty filter limits airflow and can degrade performance. Regularly replacing it ensures optimal engine operation.

Next, inspect the EGR (Exhaust Gas Recirculation) valve. It redirects a portion of exhaust gases back into the intake manifold. When malfunctioning, it may cause misfires, especially under acceleration.

If you suspect the EGR system, testing the valve and cleaning the passageways can be effective. Remember, a stuck or clogged EGR valve can impede the air-fuel mixture, causing misfires.

Step 7: Verify the Condition of Vacuum Hoses

Vacuum leaks can be elusive culprits behind misfires. The engine uses a vacuum for various functions, including controlling the fuel and air mixture. A leak can upset this balance.

To spot a vacuum leak, listen for a hissing noise while the engine runs. You can also use a smoke machine to introduce smoke into the intake. The smoke will escape where the leak is, making it visible. Replace any cracked or brittle hoses.

Step 8: Evaluate the Timing Belt or Chain

Engine timing plays a pivotal role. If the timing belt or chain slips, even slightly, it can lead to a misfire. Inspect the timing belt or chain for wear, looseness, or missing teeth. If signs of wear are evident, consider replacing them promptly.

Moreover, ensure the timing is set correctly. Incorrect timing can also result in misfires and decreased performance.

Step 9: Consider Potential Sensor Failures

Modern cars heavily rely on sensors to monitor and adjust engine conditions. A faulty sensor can send the wrong signals, leading to misfires. The primary suspects include:

  1. Mass Air Flow (MAF) Sensor: Measures the amount of air entering the engine. A dirty or failing MAF can miscalculate air, affecting combustion.
  2. Oxygen Sensors: Positioned before and after the catalytic converter, they monitor the oxygen content. Malfunction can disrupt the air-fuel mixture.
  3. Crankshaft and Camshaft Position Sensors: They monitor engine timing. If they malfunction, they can misinform the PCM, leading to misfires.

If you suspect sensor issues, use an OBD II scanner to pull any codes. This can guide you towards the problematic sensor.

Step 10: Contemplate Fuel Quality and Contamination

Low-quality fuel or contamination can also lead to misfires. Water or debris in the fuel disrupts the combustion process.

If you’ve recently refueled and problems began soon after, consider this possibility. Using a fuel additive or completely draining and refilling the tank with high-quality fuel can sometimes resolve these misfires.

Step 11: Seek Expert Help if Needed

If after all these steps, the misfire persists, it might be time to consult a mechanic. There are intricate issues that may require specialized tools or expertise. Always prioritize the safety and the health of your engine.

In conclusion, a misfire can stem from numerous causes. Diligently following these steps will aid in diagnosing and remedying the root cause. Proper maintenance and regular inspections can preemptively combat many potential misfire causes, ensuring smooth driving for years to come.

Common Mistakes While Diagnosing A P0302 Code

Check for any signs of damage in the wiring harness before replacing the spark plug and coil pack wiring. If other trouble codes are present, diagnose and repair them as well. And ensure to look for cylinder misfires as a possible cause for the problem.

P0302 engine problems troubleshooting

All of the parts mentioned above could lead to the p0302 code error and if you see any change in engine cylinder 2, make sure to replace it. Defected oxygen sensor could also be one of the reasons that can cause a fuel injector to act abnormally, so kindly check its working conditions while examining other methods.

Facts: Understanding the P0302 Code and How to Address It

  • The P0302 engine code indicates that the PCM has detected a misfire on cylinder 2, which can cause serious drivability issues, and should be addressed immediately.
  • Cylinder 2 refers to the cylinder numbered “2” in the engine arrangement and not the second cylinder in the firing order.
  • A misfire is caused by incomplete or absent combustion in one cylinder, which can be triggered by ignition system problems, fuel delivery issues, or engine mechanical issues.
  • The PCM continually monitors the crankshaft speed and will store trouble codes for misfires that happen a sufficient number of times within the 200 or 1000 rpm window.
  • Code P0302 by itself is a good indicator that the problem is with cylinder 2 only.
  • Symptoms that may be observed when only a P0302 code is stored include the check engine light on or flashing, rough running, stalling, difficulty starting the engine, foul odor coming from the exhaust, decrease in power, and excessive fuel consumption.
  • However, a cylinder 2 misfire can confuse the PCM and cause P0300 and other misfire codes to set, making diagnosis even more difficult.
  • To diagnose the problem properly, all possible causes should be checked, and if you don’t have the required DIY auto repair experience and skills, it’s best to have a professional mechanic check your vehicle.
  • The P0302 code is part of a series of misfire DTCs that range from P0301 to P0312, with each code indicating a misfire on a particular cylinder except for P0300, which implies a random misfire.
  • The P0302 code has been reported by many owners of Ford, Honda, Toyota, Dodge, and Jeep vehicles.

Cylinder 2 Misfire: In Conclusion…

If you follow all of these steps, you could quickly diagnose and fix the problem of cylinder 2 misfiring or p0302 code. Without this guidance, it will take time and money to diagnose and fix the cylinder 2 misfire engine problem. If you are stuck with a misfiring cylinder, your best option is to diagnose and fix it ASAP, before the problem becomes more severe.

Engine misfiring is a common problem that may have the potential to cause engine damage and even expensive repair costs. A reliable diagnostic guide always helps you pinpoint the root cause of this problem which you can find in this article.

Cylinder 2 Misfire: Frequently Asked Questions (FAQs)

Here are some popular FAQs:

How Do You Fix A Cylinder 2 Misfire

There are several ways to fix a cylinder 2 misfire, and some of them are given as follows. You can try changing the defective spark plugs with new ones, or fixing the vacuum leaks present in the engine cylinder. Otherwise, burned valves need to be replaced with the new ones, and be sure to replace damaged spark plugs and their wires. Meanwhile, clogged EGR tubes and valves, defective coil pack wires, camshaft sensors, and O2 sensors could all be replaced if compromised.

What Causes Cylinder 2 Misfire

Cylinder 2 misfire causes are abundant until you find the root cause of this problem. Cylinder 2 misfires can be caused by dirty or faulty spark plugs, faulty fuel injectors, a clogged air filter, or low compression in the cylinder. Besides that, you might have corroded spark plug wires, a poor EGR valve, defective PCM modules, clogged EGR, or bad piston rings.

What Does Cylinder 2 Misfire Mean

If your car is experiencing a cylinder 2 misfire, it’s essential to take action immediately to avoid costly repairs. But what exactly does cylinder 2 misfire mean? A misfire occurs when the engine fails to ignite the fuel in one or more cylinders. It can happen for several reasons, but it’s due to a spark plug or ignition system problem. Cylinder 2 misfire is a specific type of misfire that refers to the second cylinder in the engine. It’s important to note that each cylinder is numbered differently depending on the make and model of your car.

What Is A Cylinder 2 Misfire

If your check engine light is on and you’re being told you have a cylinder 2 misfire, don’t panic! A misfire is when the air/fuel mixture in the cylinders isn’t igniting properly. It can cause problems, from decreased fuel efficiency to damaging your catalytic converter. On its own, a misfire usually isn’t a huge deal. But if it’s severe or happens often, it’s something you’ll want to get fixed ASAP. A few different things could be causing your cylinder 2 to misfire. It could be a problem with the spark plug, the defective ignition coil, low compression in the engine cylinder, etc.

Can A Vacuum Leak Cause A Misfire

A vacuum leak can be caused by a bad gasket or a crack in one of the vacuum lines. When there is a vacuum leak, it will cause one or more of your engine’s functions not to operate correctly, which is why it is essential to find these leaks and repair them before severe damage can occur. A loss of vacuum valve strength will allow hot exhaust gases to escape from the manifold, reducing cylinder pressure. It, in turn, reduces the ability of the intake valves to close completely, thus allowing unmetered air into the combustion chamber and causing the misfire.

Can Bad Purge Valve Cause Misfire

If the O2 sensor detects a rich air-fuel mixture, it sends a signal to the PCM, telling the injectors to close (no fuel injected) and opening up the purge control valve. It removes excess fuel from the exhaust system to prevent flashback into the intake manifold. The PCM also monitors how long the purge control valve stays open before closing and how long it takes the engine to stumble back into operation. The purge valve inside the fuel injection system creates a vacuum to suck fuel into the cylinder. It is done during a cold start to help with the combustion process. The bad purge valve will give a misfire code. The purge valve can become stuck in the open position, resulting in a burned exhaust. This condition often causes misfires and hesitation upon acceleration.

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