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P0137 on Ford Explorer

O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)

Factory diagnostic protocol and troubleshooting wire for fault code P0137 specifically for the Ford Explorer (2020–2026, 2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP)).

Verified OEM Telemetry & Field Repair Tree
Ford Explorer2020–2026
Ford Explorer
SUV2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Explorer SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Low urgency level
Est. Repair Cost
$100 - $300 (DIY: $35 - $100)
Parts & Labor DIY
Check P0137 On Another Ford Model:
Diagnose P0137 on Specific Explorer Model Year:

1. Symptoms of P0137 on Ford Explorer

When the Engine Control Module (ECM/PCM) on your Ford Explorer (2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP)) logs fault code P0137, drivers commonly observe:

Check Engine Light on on Ford Explorer (2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP))
Downstream sensor voltage consistently below 0.15V on scan tool on Ford Explorer (2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP))
Failed emissions test on Ford Explorer (2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP))
Ford Explorer OBD-II Port Location
The 16-pin diagnostic connector is located Lower steering column dash trim. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Ford Explorer

Historical warranty claims and technical repair bulletins for Ford Explorer point to the following failure distribution:

55%
Exhaust leak upstream of or directly at the Sensor 2 bung letting in fresh air (Ford OEM Part)
25%
Faulty downstream oxygen sensor (Ford OEM Part)
12%
Short to ground in sensor signal wire (Ford OEM Part)
8%
Extremely lean exhaust condition (Ford OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Ford Explorer.

3. Step-by-Step DIY Repair Guide for Ford Explorer

01
Inspect Exhaust System for Leaks

Listen for exhaust ticking or black soot around flex pipe, flanges, and sensor bungs before the catalytic converter. on the Ford Explorer equipped with 2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP).

Required Tool: Flashlight, Jack Stands
02
Check Sensor Signal Voltage with Scan Tool

Monitor B1S2 voltage. Snap the throttle to enrich mixture; voltage should briefly spike above 0.8V. If it remains 0.0V–0.1V, sensor is defective or shorted. on the Ford Explorer equipped with 2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP).

Required Tool: OBD-II Scanner
03
Replace Downstream O2 Sensor

Unplug harness, remove old sensor with 7/8 socket, install replacement sensor and plug firmly. on the Ford Explorer equipped with 2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP).

Required Tool: O2 Sensor Socket, Ratchet
04
Clear Codes

Clear DTCs and verify B1S2 holds steady between 0.45V and 0.75V during steady highway cruising. on the Ford Explorer equipped with 2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP).

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Ford Explorer (P0137)

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Direct-Fit Replacement Part

Ford Explorer OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Ford Explorer.

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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
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Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Ford ExplorerVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Ford Explorer

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Ford Explorer:

4. Ford Explorer P0137 FAQs

What causes code P0137 to trigger on a Ford Explorer?

On the Ford Explorer (2.3L EcoBoost 4-Cyl (300HP) / 3.0L Twin-Turbo EcoBoost V6 (ST 400HP)), P0137 is most frequently caused by Exhaust leak upstream of or directly at the Sensor 2 bung letting in fresh air or Faulty downstream oxygen sensor.

Where is the OBD-II port located on my Ford Explorer?

On the Ford Explorer, the 16-pin DLC diagnostic connector is located Lower steering column dash trim. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Ford Explorer with code P0137?

Yes. Vehicle is fully drivable, but Check Engine Light will remain illuminated. Given that P0137 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.