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Home/DTC Codes/Ford/Explorer/2002-2005 4.6L V8/P0139
P0139

O2 Sensor Circuit Slow Response Bank 1 Sensor 2

2002-2005 Ford Explorer 4.6L V8 🇨🇦

Low SeverityPowertrain

Description

The downstream O2 sensor on Bank 1 is responding too slowly.

Symptoms

  • Check Engine Light
  • Failed emissions

Common Causes

  • Aging sensor
  • Contaminated sensor
  • Catalyst issue

Diagnostic Steps

  1. Monitor sensor response
  2. Check catalyst efficiency

Repair Notes

Replace downstream O2 sensor.

Related Codes

P0136O2 Sensor Circuit Bank 1 Sensor 2P0140O2 Sensor Circuit No Activity Bank 1 Sensor 2

Other Powertrain Codes

P0139 on Other Vehicles

Ford Aerostar

1990-1997 3.0L V6

Ford Aerostar

1990-1997 4.0L V6

Ford Bronco

1990-1996 4.9L I6 300

Ford Bronco

1990-1996 5.0L V8 302 Windsor

Ford Bronco

1990-1996 5.8L V8 351 Windsor

Ford Bronco

2021-2024 2.3L I4 EcoBoost

Ford Bronco

2021-2024 2.7L V6 EcoBoost

Ford Bronco Raptor

2022-2024 3.0L V6 EcoBoost

Common Questions

What does code P0139 mean on a 2002-2005 Ford Explorer?

P0139 stands for "O2 Sensor Circuit Slow Response Bank 1 Sensor 2". The downstream O2 sensor on Bank 1 is responding too slowly.

What are the symptoms of P0139 on a Ford Explorer?

Common symptoms of P0139 include: Check Engine Light, Failed emissions.

What causes P0139 on a 2002-2005 Ford Explorer?

Common causes of P0139 include: Aging sensor, Contaminated sensor, Catalyst issue.

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