Engine-Codes - Ford - P0156 2002 Ford F150

P0156 2002 Ford F150 Code - Heated Oxygen Sensor Circuit Malfunction Bank 2 Sensor 2

- Code Popularity: 5,881 Views
- Repair Importance Level: 2/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P0156 2002 Ford F150?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Exhaust gas leaks
  • Faulty Heated Oxygen Sensor 2 (HO2S2) (Downstream) Bank 2
  • Heated Oxygen Sensor 2 Bank 2 harness is open or shorted
  • Heated Oxygen Sensor 2 Bank 2 circuit poor electrical connection
  • Inappropriate fuel pressure
  • Faulty fuel injectors
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How to Fix the DTC P0156 2002 Ford F150?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0156 2002 Ford F150 code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • High Fuel Consumption

What Does the P0156 2002 Ford F150 Code Mean?

The Heated Oxygen Sensor 2 (HO2S2) (Downstream), after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air-fuel mixture (air-fuel ratio) must maintain near the ideal stoichiometric ratio. The HO2S2 output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Powertrain Control Module (PCM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S2 generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The PCM interprets Lean when the HO2S2 voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The PCM interprets Rich when the HO2S2 voltage is above 0.45 V. The P0156 code will set when the PCM detects that the HO2S2 signal voltage is out of range for an extended period.
P0156 2002 Ford F150 Code - Heated Oxygen Sensor Circuit Malfunction Bank 2 Sensor 2

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