| Table of Contents | |
| Possible Causes of P0302 & Their Repair Costs | Code P0302 indicates that the engine control module or powertrain control module has detected a misfire in cylinder #2. |
| How to Diagnose the Cause of Your P0302 Code | A P0302 code points to a misfire in an engine’s second cylinder, which several problems can trigger. The cause might be ignition-related, such as bad spark plugs or coils; fuel system issues, such as clogged injectors; mechanical problems, including vacuum leaks; or malfunctioning engine sensors. |
| Can I drive with a P0302 code? | No. A P0302 misfire can seriously damage an engine and catalytic converter with continued driving. The misfire also creates dangerous driving conditions since the vehicle may unexpectedly lose power or stall. |
| DIY | How To Fix P0302 Causes |
DIYable P0302 triggers include:
|
| P0302 Code FAQs |
Frequently asked questions:
|
An engine misfire is one of the most serious problems that impact an automobile. It can lead to catastrophic engine failure, catalytic converter damage, and eye-watering repair bills. Diagnostic trouble codes (DTCs) help pinpoint misfire sources. For instance, DTC P0302—Cylinder 2 Misfire Detected—signals that the issue involves engine cylinder #2.
There’s an entire series of P030xx codes. P0300 is a more general warning about misfires with multiple cylinders. Meanwhile, like P0302, there are cylinder-specific error codes. P0301 warns of misfires in cylinder #1, P0303 covers cylinder #3, P0304 involves cylinder #4, and P0306—you guessed it—concerns cylinder #6. These codes range from P0301 to P0312, although there aren’t too many 12-cylinder cars on the road.
A check engine light for a misfire comes on when the engine control module (ECM) or powertrain control module (PCM) detects a disruption with the timing cycle critical to the combustion process. In the case of P0302, a mechanic can zero in on cylinder #2 and adjacent areas.
It’s essential to understand that any engine misfire code, including P0302, requires immediate attention. You’ll have to pull over to a safe area, shut off the engine, and call a tow truck. Operating the car for even a brief period can cause severe engine damage, making the price of a tow look like a bargain in comparison.
But don’t assume all P0302-related repairs are expensive. Sometimes, a new spark plug or vacuum line is all it takes to correct the situation. Keep reading as we’ll explore typical symptoms to look for and common causes and repairs. This deep dive into P0302 codes will also examine what makes and models are the most vulnerable to them.
Possible Causes of P0302 & Their Repair Costs
A P0302 code raises several red flags for vehicle health and safety. Not only can these misfires inflict significant engine damage, but they also put you at risk on the road. Picture trying to merge onto a busy highway or clear an intersection when the engine suddenly loses power or cuts out—scenarios no driver wants to face.
Check out the FIXD article on the most common causes of check engine lights.
Here’s a look at the parts most likely involved with a P0302 code and how much things cost. Note that actual prices depend on the vehicle and location.
P0302 Code Triggers & Typical Repair Costs
| Part To Repair | Part / DIY Price | Mechanic Total Cost |
| Spark Plugs | $83–$112 | $212–$276 |
| Spark Plug Wires | $66–$84 | $208–$256 |
| Camshaft Position Sensor | $75–$95 | $176–$227 |
| Crankshaft Position Sensor | $96–$121 | $168–$224 |
| Vacuum Line | $50–$100 | $200–$300 |
| Ignition Coil | $161–$230 | $213–$295 |
| Fuel Pressure Regulator | $165–$195 | $266–$322 |
| Oxygen Sensor | $300–$333 | $362–$412 |
| Fuel Injector | $450–$541 | $644–$784 |
| Fuel Pump | $916–$1,042 | $166–$209 |
| Head Gasket | $815–$833 | $1,100–$1,387 |
| Catalytic Converter | $2,188–$2,284 | $2,342–$2,479 |
Here’s how different malfunctioning parts can trigger a P0302 code.
Parts Most Likely to Fail & Cause a P0302 Code
| Parts that can cause P0302 | How it could cause P0302 |
Spark Plugs Spark Plug Wires | Cylinder #2 isn’t completing its combustion cycle. |
| Ignition Coil | Faulty spark plug ignition. |
Camshaft Position Sensor Crankshaft Position Sensor Fuel Pressure Regulator | The engine control module/powertrain control module detects timing or fuel delivery issues. |
Vacuum Line Fuel Injector Oxygen Sensor | The air-fuel ratio is off-balance. |
| Fuel Pump | Cylinder #2 is fuel-starved. |
| Head Gasket | Low compression in cylinder #2. |
| Catalytic Converter | Unburnt fuel accumulates, creating excess exhaust pressure. |
Makes Commonly Affected By P0302
According to FIXD sensor data, P0302 codes are prevalent across various brands and vehicle types. That said, some manufacturers are more susceptible to these problems, with Toyota having the dishonors of first place. The Camry stands at the top of the list, with the Corolla close on its heels. The Prius also has high occurrence levels for this DTC.
Among domestic brands, Ford leads this index. In particular, the F-150 is no stranger to P0302 codes; neither is the Escape. The Fusion earns the third spot but at a medium incident rating. The Blue Oval’s cross-town rival, Chevrolet, completes the P0302 podium, starting with the Silverado 1500. Meanwhile, the Camaro and Traverse round out the standings for the Bow Tie brand.
Audi earns fourth-place status, but only one car, the A4, deserves attention for code P0302-related problems. Dodge completes the list, with the Grand Caravan being the most affected (high occurrence ratings). The Ram 1500 and Durango have a history with this DTC but at a low rate.
| Top 5 Makes Affected by P0401 | Most Affected Model(s) |
Toyota | Camry |
| Corolla | |
| Prius | |
Ford | F-150 |
| Escape | |
| Fusion | |
Chevrolet | Silverado 1500 |
| Camaro | |
| Traverse | |
| Audi | A4 |
Dodge | Grand Caravan |
| Ram 1500 | |
| Durango |
How to Diagnose the Cause of Your P0302 Code
Discovering the reason behind a check engine light requires an OBD-II scanner. Your options include the FIXD plug-in sensor and accompanying app that shows the diagnostic trouble code and common causes behind the problem. Alternatively, a basic code reader that plugs into your car’s OBD-II port will also work, but these devices only show the code, not the underlying issue that triggered the code.
For a P0302 code, there’s not much for an amateur mechanic to investigate (problems like a faulty oxygen sensor or catalytic converter are best left to a professional). Nonetheless, if you decide to explore under the hood or elsewhere, there are a few essential safety steps to follow:
- Have the right tools for a basic inspection: a flashlight, gloves, safety goggles, and a rag. Hand tools may be necessary for more detailed work.
- Park on a safe, level surface.
- Turn the car off and engage the parking brake.
- Allow the engine to cool.
Symptoms of P0302 Causes
Identifying the location of cylinder #2 gets to the heart of dealing with P0302-related symptoms. This makes dealing with a bad spark plug, spark plug wire, or oxygen sensor much easier.
Most automakers count cylinders sequentially, with #2 typically following a consistent pattern. In straight/inline engines, #2 is the second cylinder back from the front (or moving away from the serpentine belt in transverse-mounted engines).
For V-style engines with two banks, cylinder #2 is usually found on the same side as #1. After finding #1, you’ll locate #2 directly behind it. However, Ford V-style engines often have a different naming convention for cylinders. In flat/boxer engines (common in Subarus and select Porsches), cylinder #2 sits on the front left when viewed from behind, opposite #1.
For precise engine layout details, it’s best to review a service manual for your car or consult a mechanic.
Most misfire problems involve complex diagnostic steps best handled by an experienced DIYer or professional technician. Nonetheless, a novice wanting to take on a code P0302 issue can consider these areas and accompanying inspection steps.
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
What to Inspect:
Check for visible damage, carbon buildup, or unusual wear patterns.
- Remove the spark plug using a spark plug socket
- Look for: Black deposits, white chalky deposits, or damaged electrodes
- Compare to a new plug for reference.
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
What to Inspect:
Visual inspection is your first step:
- Look for cracks, burns, or worn insulation
- Check for loose connections at both ends
- Listen for clicking/arcing sounds with the engine running
Pro tip: Don’t pull wires by the cables—always grip at the boot.
- More advanced testing involves using a 12-volt tester
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
What to Inspect:
Examine cylinder #2’s ignition coil:
- Check for visible damage
- Look for oil seepage
- Test resistance with multimeter (results may not be conclusive)
For a practical test, a moderately experienced DIYer can swap coils:
- Move cylinder #2’s coil to a known good cylinder
- Place the working coil into cylinder #2
- Start the engine and scan for codes
- If the misfire moves with the original coil, you’ve found the problem
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
What to Inspect:
Check your vehicle’s manual or repair guide to find the correct sensor. Inspect it for:
- Physical damage
- Loose or corroded connections
- Proper mounting
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
- Fuel leak/smell
- Black exhaust smoke
- Backfiring
- Hard-to-start engine
What to Inspect:
Listen for:
- A loud humming from the fuel tank
- Unusual fuel smell under hood Professional testing is recommended as it requires:
- Specialized fuel pressure gauges
- Safe fuel system handling experience
Symptoms:
- Illuminated check engine light
- Higher-than-normal engine RPMs at idle
- Rough engine idle
- Engine sputtering or stalling
- Hard-to-start engine
- Abrupt transmission shifts at high RPMs
What to Inspect:
You can perform a basic check:
- Listen for hissing sounds with the engine running
- Visually inspect vacuum lines for cracks/breaks
- Spray soapy water on connections (bubbles indicate leaks)
- More thorough testing requires a smoke machine at a shop.
Symptoms:
- Illuminated check engine light
- Rough idling
- Engine stalling or hesitation
- Fuel leak/smell
- Black exhaust smoke
What to Inspect:
Locate the fuel injector for cylinder #2 and start the engine.
Check operation:
Using screwdriver method:
- Place the tip against the injector
- Listen through the handle end
- Check for regular clicking
Optional test (for experienced DIYers):
- Unplug cylinder #2 injector while running
- Note any engine sound or RPM changes
- No change suggests a faulty injector
Warning: Be careful working around a running engine.
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
- Black exhaust smoke
- Failed emissions test
What to Inspect:
Basic check:
- Look for damaged wiring
- Check for loose connections. However, proper diagnosis requires:
- Professional scan tool
- Live data monitoring
- A mechanic can verify the O2 sensor operation
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
- Hard-to-start engine
- Whirring noise from the fuel tank area
- Overheating
What to Inspect:
Listen for:
- NO whirring sound when turning the key to “ON” (a healthy pump should make a brief whirring noise)
- Inconsistent or no pump operation while running
Warning signs:
- Sputtering under acceleration
- Loss of power at highway speeds
- Engine stalling or hard to start
- Surging at steady speeds
Professional testing needed for:
- Fuel pressure testing
- Flow rate verification
- Electrical system checks
Symptoms:
- Illuminated check engine light
- Rough idling
- Engine stalling or hesitation
- Overheating
- White or gray exhaust smoke
- Milky oil
- Coolant loss
What to Inspect:
A simple block leak test can be done at home with a store-bought kit.
For a complete check, have a mechanic do a compression test.
Symptoms:
- Illuminated check engine light
- Rough idling
- Reduced fuel economy
- Engine stalling or hesitation
- Failed emissions test
- Rattling noise
- Sulfur smell
What to Inspect:
Get a professional mechanic to check catalytic converter problems; emissions work requires expert skills.
Can I drive with Code P0302?
Quick answer: No. Don’t drive with a P0302 code.
Driving a car not in peak operating condition is hazardous, especially if a misfire occurs. An engine that hesitates or stalls is a recipe for an on-road disaster when there’s a power loss on the highway or at an intersection.
The other significant risk is potential damage to critical components. Pistons and cylinder walls are especially vulnerable to a misfire. In addition, misfires often lead to unburnt fuel entering the catalytic converter, which destroys internal elements that control emissions.
Here’s a more detailed look at driveability with a P0302 code.
| Causes | Can I Drive? | Risks / Safety / Performance |
|---|---|---|
|
Defective Spark Plug |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Can lead to power loss and cylinder damage. |
|
Damaged Spark Plug Wire |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Interferes with proper spark plug function, causing poor engine operation and a risk of power loss. |
|
Bad Ignition Coil |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
May cause backfiring, severe loss of power during acceleration, and potential internal engine damage. |
|
Faulty Camshaft or Crankshaft Position Sensor |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Can lead to sudden stalling in traffic and may result in catastrophic engine damage if valve timing is affected.
|
|
Defective Fuel Pressure Regulator |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Excess fuel may wash the cylinder walls, leading to oil contamination and severe internal engine damage. |
|
Vacuum Leak |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Unmetered air entering the system can cause lean running conditions that may burn valves or damage internal components. |
|
Bad Fuel Injector |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Inconsistent fuel delivery creates lean conditions in the affected cylinder, potentially leading to burnt valves and damaged pistons. |
|
Faulty Oxygen Sensor |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
This can lead to poor performance, reduced power, and possible damage to other engine components.
|
|
Defective Fuel Pump |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Incorrect fuel trim adjustments can create long-term damage to engine components due to imbalanced air-fuel mixtures. |
|
Leaking Head Gasket |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Coolant entering the combustion chamber can cause hydrolock, bent connecting rods, and catastrophic engine failure. |
|
Malfunctioning Catalytic Converter |
No. Don’t drive with a P0302 code to avoid unsafe conditions and significant damage. |
Excessive back pressure can crack the exhaust manifold, damage engine valves, and potentially cause engine overheating |
DIY | How To Fix P0302 Causes
As mentioned, most remedies for a P0302 code will require a mechanic’s involvement. But this doesn’t mean a moderately capable amateur can’t take a crack at some of the causes.
However, DIYers must recognize their limitations. Don’t proceed with a repair if there’s any degree of uncertainty. You want to avoid injury or more damage at all costs.
Possible Cause: Defective Spark Plug
What is it?
Spark plugs are essential to every gasoline engine. A fouled or defective spark plug is a common cause of engine misfires and could be the source of a cylinder #2 issue.
How hard is it to fix?
Difficulty Level: Easy/Moderate
Fortunately, replacing a spark plug is easy if you can get to it. Some transverse-mounted engines have spark plugs located near the firewall, making access challenging. You’ll need a few tools and supplies: replacement spark plugs (it’s best to replace them all), a gap gauge, a torque wrench (to avoid overtightening), a spark plug socket, a ratchet handle, and anti-seize for the spark plug threads. A spark plug boot puller can make disconnecting the spark plug wires simpler, and spark plug boot (dielectric) grease will make the task easier in the future.
Cost of Repairs
On average, a new set of spark plugs costs $83–$112. Tools and supplies are separate.
Possible Cause: Damaged Spark Plug Wire
What is it?
Like many things under the hood, a spark plug wire can degrade over time, affecting how the spark plug functions and leading to an engine misfire.
How hard is it to fix?
Difficulty Level: Easy/Moderate
Replacing a spark wire is typically straightforward. As with spark plugs, the greatest challenge is being able to get to the connection points. Once you have access, a spark plug boot puller (see above) and spark plug boot grease can help with the task. Wire loom spacers can ensure the new wires are correctly positioned to prevent arcing to the ground and cross-firing, which can damage other components.
If you’re working beyond cylinder #2, be sure to pay attention to the placement and length of each wire—usually, if one wire needs replacing, the others aren’t far behind. So, you might as well replace all the spark plugs while you’re at it.
Cost of Repairs
On average, a new set of spark plugs costs $66–$84. Tools and supplies are separate.
Possible Cause: Vacuum Leak
What is it?
Proper air-fuel mixture is one vital element of a smooth-running engine. A vacuum leak creates an imbalance that can lead to a higher-revving engine and code P0302.
How hard is it to fix?
Difficulty Level: Moderate
The greatest challenge to fixing a vacuum leak is finding the problem. The soapy water spray technique (see above) only goes so far and can require more sophisticated methods that are best left to experienced hands. While replacing some vacuum lines is relatively easy, a vacuum leak involving a gasket, intake manifold, or other components requires professional intervention.
Cost of Repairs
Depending on the vehicle and the component, a replacement vacuum line will cost $50 to $150.
Other DIY Considerations for Code P0302
More advanced DIYers will find the above tasks to be no-brainers. If this is the case, you might be ready for more involved repairs like swapping out an oxygen sensor or fuel pump. You’ll need the right tools and the ability to access difficult-to-reach components.
Before dealing with any code P0302-related repair, check whether your car is under warranty. You can save money by letting the automaker handle the work. In addition, research if there are any technical service bulletins (TSBs) for your car. TSBs are official repair/correction notices issued by the manufacturer that cover specific problem areas. You can research this online or contact a dealer.
P0302 Code FAQs
What makes and models does code P0302 affect the most?
Here’s a breakdown of the vehicles most affected by code P0302, according to FIXD sensor data collected in 2023.
| Make | Model | Occurrence Frequency |
| Audi | A4 | High |
| Chevrolet | Silverado 1500 | High |
| Dodge | Grand Caravan | High |
| Ford | F-150 | High |
| Ford | Escape | High |
| Nissan | Altima | High |
| Subaru | Outback | High |
| Toyota | Camry | High |
| Toyota | Corolla | High |
| Toyota | Prius | High |
| Volkswagen | Jetta | High |
| Volkswagen | Passat | High |
| Volkswagen | Tiguan | High |
What is a P0302 engine code?
P0302 is a diagnostic trouble code indicating that the engine has a misfire in cylinder #2, meaning the cylinder isn’t producing proper power during combustion. This code is considered serious since misfires can quickly lead to engine damage and unsafe driving conditions if not addressed.
What are the risks of a cylinder 2 misfire?
A cylinder 2 misfire creates multiple risks: immediate engine damage from unburned fuel washing down cylinder walls, catalytic converter damage from raw fuel entering the exhaust system, and dangerous driving conditions due to power loss that could occur during critical moments like highway merging or intersection crossings.
What is P0302 on Ford vehicles?
P0302 indicates a misfire detected in cylinder #2 of a Ford engine. This is a common issue across many Ford models and requires prompt attention to prevent engine damage. The Ford F-150 and Escape are especially vulnerable to P0302 codes.
References:
Repair-cost estimates, repairpal.com (various dates). November 12, 2024, from repairpal.com.
Dave Goldberg is an automotive journalist and lifelong car fanatic. He writes for numerous enthusiast and business outlets and is an ongoing contributor to HotCars.com, one of the most popular car culture websites. When he’s not writing or driving, Dave is either under a hood or asleep. His credentials include a BA in Journalism from The George Washington University.
