P0172 on Toyota 4Runner: Fix & DLC Location
Factory diagnostic troubleshooting wire for fault code P0172 (System Too Rich (Bank 1) - Symptoms, Causes & Step-by-Step Fix) specifically on the Toyota 4Runner (2020–2026, 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl).
1. Symptoms of P0172 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 P0172, 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
Use dedicated MAF cleaner to remove carbon buildup from sensor wires. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Use live OBD-II scanner data; negative trims beyond -10% indicate the ECU is cutting fuel. on the Toyota 4Runner equipped with 4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl.
Perform a fuel pressure leak-down test to identify injectors leaking raw gasoline into cylinders while parked. 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 P0172 FAQs
What causes code P0172 to trigger on a Toyota 4Runner?
On the Toyota 4Runner (4.0L V6 (1GR-FE) / 2.4L i-FORCE Turbo 4-Cyl), P0172 is most frequently caused by Faulty or leaking fuel injector or Contaminated Mass Air Flow (MAF) sensor.
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 P0172?
Driveable short distances, but unburnt fuel can damage catalytic converters. Given that P0172 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.