P0303 on Toyota 4Runner: Fix & DLC Location
Factory diagnostic troubleshooting wire for fault code P0303 (P0303: Cylinder 3 Misfire Detected) specifically on the Toyota 4Runner (2020–2026, 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl).
1. Symptoms of P0303 on Toyota 4Runner
When the Engine Control Module (ECM/PCM) on your Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl) logs fault code P0303, drivers commonly observe:
2. Most Likely Causes on Toyota 4Runner
Historical warranty claims and technical repair bulletins for Toyota 4Runner point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Toyota 4Runner
Interface with the diagnostic port or system console using verified scanning hardware. Record freeze-frame data, active sub-codes, and timestamps to isolate whether P0303 is static or intermittent. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Visually inspect the physical component (Cylinder 3 Coil Pack / Injector), connector pins, and associated wiring harnesses for signs of corrosion, thermal melting, or loose grounding clips. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Measure reference voltages and resistance thresholds against manufacturer factory specifications. Replace any component failing nominal impedance tolerances. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Install genuine OEM replacement hardware or execute registry / service commands. Ensure all mounting bolts are torqued to factory specifications. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Erase the fault code from non-volatile memory. Perform a standard verification cycle (e.g. 15-minute mixed drive or system stress benchmark) to ensure monitors reset to 'Ready' state without recurrent fault flags. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Other Common Fault Codes on Toyota 4Runner
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota 4Runner:
4. Toyota 4Runner P0303 FAQs
What causes code P0303 to trigger on a Toyota 4Runner?
On the Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl), P0303 is most frequently caused by Component aging, oxidation, or degraded internal circuit element (Cylinder 3 Coil Pack / Injector) or Wiring harness abrasion, loose terminal pin, or ground voltage float.
Where is the OBD-II port located on my Toyota 4Runner?
On the Toyota 4Runner, the 16-pin DLC diagnostic connector is located Lower dashboard near parking brake mechanism. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Toyota 4Runner with code P0303?
No. Immediate shutdown / repair required to prevent permanent hardware destruction or total system lockup. Given that P0303 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.