P0135 on the 2022 Ford Explorer
The 2022 Ford Explorer features the 2.3-liter EcoBoost turbocharged inline-four as its standard engine, producing 300 horsepower. The Explorer ST and Platinum trims use the 3.0L twin-turbo V6. A P0135 code points to a heater circuit malfunction in the Bank 1 upstream O2 sensor. On the 2.3L four-cylinder, this is the only upstream sensor, situated near the turbocharger in a high-temperature exhaust zone.
RWD Platform and Exhaust Routing
The sixth-generation Explorer uses a rear-wheel-drive-based platform (CD6) with the engine mounted longitudinally. The exhaust system routes underneath the vehicle differently than transverse-engine competitors. The O2 sensor wiring follows the exhaust path along the tunnel and frame, where it can be exposed to road debris and environmental hazards. The turbo-area sensor location experiences some of the highest temperatures in the entire exhaust system.
Common Causes
- Heater element failure (High Likelihood): At two to three years old, the Motorcraft sensor heater coil can fail from the demanding turbo-adjacent thermal environment. The 2.3L EcoBoost generates high exhaust gas temperatures, especially under load with the Explorer's 5,600-pound towing capacity being utilized.
- Wiring damage near the turbo (Medium Likelihood): The sensor harness runs through an area of intense heat. Insulation degradation can occur even in a relatively short time if heat shielding is not providing full protection.
- Blown heater fuse (Medium Likelihood): The power distribution box under the hood contains the O2 heater fuse. A quick check takes seconds and can identify the cheapest possible fix.
- Connector or ground issue (Low Likelihood): Corrosion or a loose connection at the sensor connector or at ground points can disrupt the heater circuit. Inspect for moisture intrusion and corroded pins.
Diagnosis
Warranty Coverage
The 2022 Explorer is within the 8-year/80,000-mile federal emissions warranty. Visit your Ford dealer for a free O2 sensor diagnosis and repair.
Self-Diagnosis
Check the heater fuse first. Then locate the upstream O2 sensor on the exhaust manifold near the turbo. The Explorer's longitudinal engine layout means working from the side of the engine bay or from underneath. Disconnect the sensor and test heater resistance: 3 to 15 ohms is normal for Motorcraft. Open circuit confirms a dead heater.
Repair Costs
Under warranty: free. Out of pocket: Motorcraft sensor $70 to $140, shop labor $100 to $170. Total: $170 to $310. DIY is feasible but requires navigating the turbo components in the longitudinal engine bay. Budget 45 to 60 minutes.
Three-Row SUV Considerations
The Explorer is a family hauler that makes frequent short trips. Each cold start with a failed heater extends the open-loop fuel period, wasting fuel and increasing emissions. The EcoBoost engine's efficiency advantage is compromised without proper O2 sensor function. Since the repair is free under warranty, take advantage of the coverage and restore your Explorer to optimal operation.