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P0302
Difficulty: EasyTime: 2-3 hoursUpdated: March 10, 2025

2022 Toyota 4Runner P0302 — Cylinder 2 Misfire Detected

The P0302 diagnostic trouble code on your 2022 Toyota 4Runner indicates a problem with the cylinder 2 misfire detected. This OBD-II code is part of the powertrain diagnostic system and specifically relates to the cylinder 2 misfire detected on your 4Runner's 4.0L 1GR-FE V6 engine, which features VVT-i (Variable Valve Timing intelligent) technology and produces 270 horsepower. Understanding this code and properly addressing it is essential for maintaining your vehicle's performance, fuel efficiency, and emissions compliance.

What Does Code P0302 Mean?

The P0302 code sets when the Powertrain Control Module (PCM) detects a malfunction in the cylinder 2 misfire detected circuit or component. In your Toyota 4Runner, this system works in conjunction with multiple sensors and control modules including the ECM, TCM (if equipped with automatic transmission), and the instrument cluster. The P0302 code can be triggered by electrical failures, mechanical issues, vacuum leaks, or sensor malfunctions.

The Toyota 4Runner is known for its rugged off-road capability and reliability. Your 2022 4Runner came equipped with either the 4.0L 1GR-FE V6 engine, which features VVT-i (Variable Valve Timing intelligent) technology and produces 270 horsepower, paired with a 5-speed automatic (A750F) or 6-speed manual on some models. Understanding your specific powertrain configuration helps in accurate diagnosis and repair.

Common Symptoms of P0302 in Toyota 4Runner

When your 2022 Toyota 4Runner stores the P0302 trouble code, you may experience one or more of the following symptoms:

Primary Symptoms

  • Check Engine Light illuminated on the dashboard
  • Rough idle or engine stalling
  • Decreased fuel economy
  • Reduced engine power or acceleration hesitation
  • Engine misfire or stumbling during acceleration
  • Unusual noises from the engine compartment
  • Difficulty starting the vehicle

Model-Specific Considerations for 4Runner

The Toyota 4Runner's body-on-frame construction and off-road-focused design mean that certain components experience more wear and tear, especially if the vehicle is used for serious off-roading. The Kinetic Dynamic Suspension System (KDSS) on some models can affect how certain sensor readings are interpreted. Additionally, if your 4Runner is equipped with the optional TRD supercharger (available on some V6 models), there are specific considerations for related components.

The A750F automatic transmission in V6 models has its own TCM that communicates with the main ECM. If the P0302 code is related to transmission functions, you may also see other transmission-specific codes.

Secondary Symptoms

  • Failed emissions test due to incomplete catalytic converter operation
  • Fuel odor from the exhaust or under-hood area
  • Black smoke from exhaust
  • Oxygen sensor heater circuit failures (if related to emissions)
  • Battery drain due to affected electrical components

Diagnostic Procedures for P0302

Proper diagnosis of the P0302 code requires systematic testing. Here is the recommended diagnostic approach for your 2022 Toyota 4Runner:

Step 1: Preliminary Inspection

Begin with a thorough visual inspection:

  1. Check all vacuum lines for cracks, disconnections, or deterioration
  2. Inspect wiring harnesses for damaged, chafed, or disconnected wires
  3. Examine sensor connectors for corrosion, bent pins, or moisture intrusion
  4. Check for proper grounding of ECM and related components
  5. Inspect the gas cap for proper sealing and function
  6. Look for obvious signs of damage from off-road use (4Runners are often subject to undercarriage impacts)

Step 2: OBD-II Scan Analysis

Using a professional-grade OBD-II scan tool:

  1. Record all stored trouble codes (not just P0302)
  2. Note any pending or intermittent codes
  3. Check freeze frame data to understand conditions when code set
  4. Monitor live data streams from related sensors
  5. Clear codes and perform test drive to confirm recurrence
  6. Record fuel trims and compare to specifications

Step 3: Electrical Testing

Using a digital multimeter and wiring diagram:

  1. Test reference voltage at affected sensor (typically 5V or 12V)
  2. Check ground circuit integrity at ECM and sensors
  3. Measure resistance of affected component
  4. Test for short circuits to ground or power
  5. Verify signal circuit voltage drops under load
  6. Check fuse boxes and relays related to affected system

Step 4: Component Testing

Based on initial findings:

  1. Test sensors individually against specifications
  2. Check fuel pressure at rail (key on, engine off and running)
  3. Inspect mass airflow sensor for contamination
  4. Test EGR valve operation and passages
  5. Verify catalytic converter efficiency with exhaust gas analyzer
  6. Check mass airflow sensor operation and output values

Repair Strategies

Based on your diagnostic findings, here are the common repair procedures for P0302 on your Toyota 4Runner:

Sensor Replacement

If diagnostic testing reveals a faulty sensor:

Replacement Procedure:

  1. Disconnect negative battery terminal
  2. Locate and access the affected sensor
  3. Disconnect electrical connector
  4. Remove mounting hardware (note proper torque specs)
  5. Install new OEM-quality replacement sensor
  6. Reconnect electrical connector
  7. Clear trouble codes with scan tool
  8. Perform relearn procedure if required

Recommended Parts for Toyota 4Runner:

  • Use OEM sensors from Denso, Toyota Genuine Parts, or AC Delco
  • Avoid aftermarket sensors that do not meet OEM specifications
  • Consider using OEM connectors and pigtails for electrical repairs
  • For 4Runners with high mileage, carry spare sensors on trail rides

Wiring Repair

For wiring-related issues:

  1. Repair or replace damaged wiring using appropriate wire gauge
  2. Use proper crimping tools and heat-shrink connectors
  3. Apply dielectric grease to connections to prevent future corrosion
  4. Secure wiring harnesses away from heat sources and moving parts
  5. For off-road use, consider additional protection for vulnerable wiring

Control Module Diagnosis

If ECM/PCM issues are suspected:

  1. Verify all power and ground supplies to the module
  2. Check for software updates from Toyota
  3. Perform module reset and relearn procedures
  4. Considerused ECM from identical vehicle as last resort
  5. Professional reprogramming may be required for module replacement

Torque Specifications for Toyota 4Runner

Proper torque specifications are critical for reliable repairs:

Sensor Mounting

  • Mass Airflow Sensor mounting bolts: 71 in-lbs (8 Nm)
  • Crankshaft Position Sensor: 14 ft-lbs (19 Nm)
  • Camshaft Position Sensor: 14 ft-lbs (19 Nm)
  • Oxygen Sensor (前置氧传感器): 33-41 ft-lbs (44-56 Nm)
  • Engine Coolant Temperature Sensor: 20 ft-lbs (27 Nm)

Fuel System

  • Fuel injector retainer bolts: 71 in-lbs (8 Nm)
  • Fuel rail mounting bolts: 14 ft-lbs (19 Nm)
  • Fuel pressure regulator: 22 ft-lbs (30 Nm)
  • Mass airflow sensor assembly: 71 in-lbs (8 Nm)

Emission Components

  • EGR valve mounting bolts: 14 ft-lbs (19 Nm)
  • EGR pipe fittings: 33 ft-lbs (44 Nm)
  • Catalytic converter mounting bolts: 33-41 ft-lbs (44-56 Nm)
  • EVAP canister purge valve: 22 ft-lbs (30 Nm)
  • Gas cap: 25 in-lbs (2.8 Nm)

General Engine

  • Engine mount bolts: 47 ft-lbs (64 Nm)
  • Intake manifold bolts: 15 ft-lbs (20 Nm) in sequence
  • Throttle body mounting bolts: 71 in-lbs (8 Nm)
  • Sensor electrical connectors: properly seated and locked

Prevention and Maintenance Tips

To prevent future P0302 codes and maintain optimal performance:

Regular Maintenance Schedule

  • Replace air filter every 15,000-30,000 miles depending on conditions
  • Use Toyota Genuine oil and filter for your 4Runner's engine
  • Replace spark plugs at manufacturer-recommended intervals
  • Inspect and replace vacuum lines at first sign of deterioration
  • Keep PCV valve and system clean and functional

Off-Road Considerations

The Toyota 4Runner excels at off-roading, but this use places additional stress on components:

  • After river crossings, check all electrical connections for water intrusion
  • Inspect sensors and wiring after tree branch impacts
  • Use skid plates to protect undercarriage components
  • After deep water or mud, clean wheel speed sensors and brake components
  • Check for proper operation of KDSS system if equipped

Long-Term Storage

  • Keep fuel system full to prevent condensation
  • Use fuel stabilizer if vehicle sits for extended periods
  • Disconnect battery if storage exceeds 30 days
  • Start engine weekly and bring to operating temperature

When to Seek Professional Help

While many P0302 diagnostics can be performed by experienced DIY mechanics, certain situations require professional assistance:

Professional Required When:

  • Multiple control modules show communication failures
  • ECM/PCM replacement or reprogramming is needed
  • Transmission-related codes require TCM diagnosis
  • Complex wiring harness repairs are needed
  • KDSS or other advanced systems require calibration
  • Emissions testing failure with no clear cause
  • If diagnosis points to internal engine problems

Choosing a Repair Shop

  • Look for shops with Toyota-specific diagnostic equipment
  • Ask about technician certifications (ASE, Toyota-specific training)
  • Request explanation of diagnostic process before authorizing repairs
  • Get written estimates for all repairs
  • Ask about warranty on parts and labor

Cost Considerations for P0302 Repair

The cost to repair P0302 on your 2022 Toyota 4Runner varies based on the root cause:

Common Repairs

  • Sensor replacement: $50-$400 depending on sensor type
  • Wiring harness repair: $100-$500 depending on extent
  • Vacuum line replacement: $20-$150
  • Fuel injector cleaning/replacement: $50-$300 per injector
  • EGR cleaning/replacement: $100-$400
  • Mass airflow sensor replacement: $150-$350

Complex Repairs

  • ECM/PCM replacement: $500-$1500+ including programming
  • Catalytic converter replacement: $500-$2000 depending on model
  • Transmission control module: $300-$800
  • Complex wiring harness: $500-$2000+

Conclusion

The P0302 Cylinder 2 Misfire Detected code in your 2022 Toyota 4Runner should not be ignored. While your 4Runner is known for its legendary reliability, proper maintenance and prompt attention to diagnostic codes will ensure many more years of trouble-free operation, whether you are commuting to work or tackling challenging off-road trails.

The 4.0L 1GR-FE V6 engine, which features VVT-i (Variable Valve Timing intelligent) technology and produces 270 horsepower in your 4Runner is a robust powertrain, but it requires proper maintenance and prompt attention to any check engine light issues. Use OEM-quality replacement parts and follow manufacturer-recommended procedures for the best results.

If you are not comfortable performing these diagnostics and repairs yourself, consult a qualified automotive technician with experience in Toyota/Lexus products. The cost of professional diagnosis is often far less than the potential cost of further damage caused by delaying repairs.

For more information about your specific 2022 Toyota 4Runner, consult your owner's manual or contact your local Toyota dealership service department.

This guide is for informational purposes only. Always refer to your vehicle's service manual and consult with qualified professionals for specific diagnostic and repair procedures. Torque specifications may vary by engine variant and model year.