P0302 Code: Toyota Camry (2018-2024) - Causes, Symptoms & Fixes

Important data note

• The real NHTSA dataset provided here for 2018-2024 Toyota Camry shows one owner complaint, but it is for P0442 (evaporative system small leak) and not for P0302.
• Official recalls in the dataset: No recalls found in NHTSA database.
• There are no P0302 entries in the supplied complaint data. This guide therefore uses general, experience-based diagnostic knowledge for P0302 on Camry 2018-2024, with clear notes about data limitations.

CODE MEANING AND SEVERITY

• Code meaning: P0302 = Cylinder 2 Misfire Detected.
• What it means technically: The powertrain control module (PCM) has detected that cylinder 2 is not combusting correctly. It senses a missing or weak ignition/combustion event based on abnormal readings (such as irregular crankshaft position signals, misfire counters, or spark/fuel anomalies).
• Severity and symptoms you should expect:
  • Rough idle or engine shake, especially at low rpm.
  • Lack of power or hesitation during acceleration.
  • Potential increase in exhaust emissions and reduced fuel economy.
  • Check Engine light (MIL) illuminated; may occur under load or intermittently.
  • Repeated misfires can lead to unburned fuel entering the catalytic converter, risking damage if left unfixed for long periods.
• Important note: Misfire on cylinder 2 can indicate problems from ignition, fuel delivery, air intake, or mechanical condition. Treat promptly to avoid catalytic converter damage and rough driving.

COMMON CAUSES ON TOYOTA CAMRY (2018-2024)

• Ignition-related
  • Worn or fouled spark plug on cylinder 2.
  • Faulty ignition coil or coil-on-plug secondary wiring/boot on cylinder 2.
  • Damaged ignition coil pack wiring or connector.
• Fuel-related
  • Malfunctioning fuel injector for cylinder 2 (stuck, leaking, or not opening properly).
  • Low or inconsistent fuel pressure affecting cylinder 2.
• Air and vacuum-related
  • Vacuum leak or cracked intake/PCV hose affecting cylinder 2 air/fuel mixture.
  • MAF sensor or intake tract contamination causing inaccurate air readings.
• Combustion/engine mechanical
  • Low compression in cylinder 2 due to valve seat leakage, worn piston rings, or head gasket issue.
  • Timing-related concerns (rare on Camry unless timing chain wear or cam phaser issue is present).
• Miscellaneous
  • Faulty cam/crank sensor data affecting knock/misfire detection.
  • Dirty or contaminated fuel causing intermittent misfire symptoms.
• Practical note for Camry models: The 2018-2024 Camry covers both the 2.5L 4-cylinder and the 3.5L V6 options. Cylinder misfire codes map similarly (cylinder numbering varies by engine type), but the underlying causes (spark, injector, compression, vacuum) remain the same in principle. Always verify cylinder numbering for your specific engine when performing swaps or inspections.

SYMPTOMS SPECIFIC TO P0302 (Cyl. 2 Misfire)

• Visible or audible rumble or shaking at idle, more noticeable when engine is cold.
• Hesitation or stumble during acceleration, especially at light throttle.
• Possible MIL illumination with a P0302 stored or pending.
• If the misfire is severe or persistent, you may notice reduced engine smoothness and lower power output.

DIAGNOSTIC STEPS (STAGE-BY-STAGE)

Before you start, ensure you have basic safety gear and an OBD-II scanner. If you are not comfortable performing these steps, seek a professional.

Phase A: Confirm and gather data

• Retrieve the code with a reputable OBD-II scanner and note any freeze-frame data.
• Check for additional codes (P0300, P0301, P0303, P0304, etc.) that might indicate multiple misfires or a subset issue.
• Review engine operating data in live mode: misfire counters, rpm, fuel trims (short-term and long-term), ignition coil primary/secondary currents if your tool supports it, and misfire history by cylinder.

Phase B: Visual and quick checks

• Inspect cylinder 2 spark plug: fouling, oil on plug, electrode wear. Replace if suspect.
• Inspect cylinder 2 ignition coil and its boot/wiring: looseness, cracks, corrosion on connector, damaged boots.
• Check for obvious vacuum leaks around the intake manifold, PCV valve, hoses, and intake boot near cylinder 2 area.
• Inspect wiring harness and connectors to cylinder 2 coil and injector for damage or loose connections.

Phase C: Targeted component testing (swap and observe)

• Spark plug/coil swap test:
  • Swap the spark plug and/or ignition coil from cylinder 2 with another cylinder (e.g., cylinder 4) one at a time.
  • After swapping, clear codes and drive to see if the misfire follows the component (P0302 moves to P0304 if the cylinder 4 now misfires) or remains on cylinder 2 (which points toward a cylinder-2 specific issue such as injector, compression, or wiring to cylinder 2).
• Fuel injector check:
  • Check injector electrical resistance and a known-good spec for the cylinder 2 injector.
  • If possible with your scanner, observe injector pulse width and duty cycle for cylinder 2; look for abnormally long/short pulse or lack of activity.
  • If available, perform a noid-light test to ensure injector is receiving the proper electrical signal.
• Fuel system pressure:
  • Measure fuel pressure at rail to ensure it meets spec for your Camry engine; a drop in pressure can cause misfires under load.
• Air intake and vacuum:
  • Perform a thorough check for leaks around cylinder 2’s intake path. A smoke test is ideal if available.
• Compression test or leak-down test (Phase D if needed)
  • If swap tests indicate the plug/coil is OK, perform a compression test on cylinder 2 and compare to the other cylinders. A significant loss (commonly >15% lower) suggests mechanical problem (valve, piston rings, head gasket, or seating issue).

Phase D: Mechanical and supporting tests (if needed)

• If compression is low on cylinder 2, isolate the cause:
  • Valve seating or burnt valve: often requires compression test with cylinder leakage test to determine if the leak is past the valve.
  • Head gasket or head issues: typically indicated by persistent compression loss with other symptoms; may require more extensive service.
• Check timing components if there are signs of timing chain wear or a discrepancy in cam/crank timing data (more common in engines with high mileage or timing chain issues).

Phase E: Confirmation and documentation

• Clear the codes after repairing and drive a few miles to confirm no reoccurrence.
• If issues persist, escalate to professional diagnostics, especially for potential injector or mechanical issues.

RELATED CODES (context for diagnosis)

• P0300: Random/Multiple Cylinder Misfire Detected — can accompany P0302 if multiple cylinders are affected.
• P0301, P0303, P0304, P0305, P0306: Individual cylinder misfire codes for cylinders 1, 3, 4, 5, and 6 respectively; in a 4-cylinder Camry these may map differently depending on engine, but the underlying causes are similar.
• Other related DTCs that may appear with misfire symptoms: P0171/P0174 (Fuel Trim), P0101 (Mass Air Flow), P030x rarely co-occurring with ignition system codes if multiple issues exist; O2 sensor and catalytic converter codes may surface if misfire is prolonged.

REPAIR OPTIONS AND COSTS (2025 prices)

Prices vary by region, dealer vs independent shop, and engine variant (2.5L 4-cyl vs 3.5L V6). The estimates below are approximate ranges you may encounter in 2025.

• Spark plug replacement (cylinder 2 only, or as part of a multi-plug replacement)

  • Parts: $8–$25 per plug (OEM or high-quality aftermarket).
  • Labor: 0.5–1.0 hour.
  • Typical total (single plug or when replacing more plugs as part of a service): roughly $120–$250. If you’re replacing just cylinder 2’s plug and the shop charges minimum, expect around $100–$180.

• Ignition coil replacement (cylinder 2)

  • Parts: $40–$140.
  • Labor: 0.5–1.0 hour.
  • Typical total: $120–$280.

• Fuel injector (cylinder 2)

  • Parts: $60–$250 (OEM or higher-grade aftermarket; port injector typical range).
  • Labor: 0.5–2.0 hours depending on accessibility and engine variant.
  • Typical total: $200–$600.
  • Note: If the injector is failing, some shops offer a cleaning service (less expensive than replacement) with variable effectiveness.

• Fuel system pressure test and vacuum/air intake repairs

  • PCV valve, hoses, gaskets: $20–$200 depending on parts and labor.
  • Vacuum leak repairs can range $100–$400 if a manifold gasket or related hose is involved.

• Compression test, leak-down test

  • If performed by a shop: typically $100–$200 (labor to remove components as needed plus test equipment). Used to determine mechanical issues.

• Major mechanical (valve jobs, head gasket, or severe compression loss)

  • Range: $1,500–$4,000+ depending on the exact failure and whether it involves a head gasket, valve job, or-engine removal.

• Summary guidance

  • If the issue is ignition or fuel delivery (plug/coil/injector), expect modest-to-moderate costs (roughly $100–$600 depending on the component and whether you replace one or multiple items).
  • If compression or mechanical valve issues are found, costs rise substantially (often several thousand dollars).
  • Always obtain a repair estimate that itemizes parts and labor before authorizing work.

DIY vs PROFESSIONAL

• Do-it-yourself-friendly checks
  • Visual inspection of spark plug and coil on cylinder 2.
  • Spark plug and coil swap test to determine if misfire follows the component.
  • Basic fuel system checks (verify injector electrical connection, measure resistance of injector).
  • Visual vacuum leak checks around intake and PCV system.
  • Compression test or leak-down test if you have the tools and experience.
• When to call a professional
  • If the misfire persists after plug/coil/injector checks, or if fuel pressure testing, compression testing, or leak-down testing is required.
  • If you are unsure about working with high-pressure fuel systems, advanced ignition diagnostics, or head/gasket concerns.
  • If the vehicle is under warranty or if you lack the diagnostic tools to interpret live data and misfire counters.
• Safety considerations
  • Disconnecting electrical connectors and working around fuel systems can be hazardous. Use appropriate PPE and ensure the vehicle is secured and cooled before service.

PREVENTION

• Regular maintenance to minimize misfires:
  • Use quality plugs and coils rated for your Camry engine; replace spark plugs at Toyota-recommended intervals or if guidelines indicate wear.
  • Keep ignition wiring and coil connectors clean and free of corrosion; replace damaged boots or wiring harness as needed.
  • Maintain fuel injectors: use good-quality fuel, consider injector cleaning if recommended by Toyota service literature (without overdoing cleansing agents that could harm seals).
  • Address vacuum leaks promptly: inspect PCV system and intake hoses for cracks or disconnections; replace gaskets if necessary.
  • Maintain proper air intake and MAF/air filter condition; clean MAF sensor if it’s indicated by service data (use manufacturer-approved cleaners).
• General practices:
  • Monitor fuel trim readings with an OBD scanner; sudden, sustained abnormal trims often point to an upstream air/fuel issue.
  • Perform regular inspections during routine maintenance and address any rough idle or power loss promptly to avoid catalytic converter damage.

Data limitations and transparency

• The provided data does not include a P0302 complaint or any P0302-related recall information for 2018-2024 Camry. The guide therefore relies on general diagnostic knowledge for P0302, with explicit caveats about data limitations.
• If you encounter a P0302 on your Camry and the above steps don’t resolve it, consider pulling service bulletins (TSBs) for your exact engine variant and VIN, and consult a Toyota-certified technician who can access Toyota’s diagnostic databases for more engine-specific guidance.

If you’d like, I can tailor the diagnostic steps to your exact Camry variant (2.5L 4-cylinder vs 3.5L V6) and provide a shorter, engine-specific checklist.