P1166 2002 HYUNDAI SANTA FE – O2 Sensor System Lambda Controller at Limit, Bank 1

P1166 2002 HYUNDAI SANTA FE Possible Causes

  • Air leak or restriction in the intake or exhaust system
  • Dirty engine oil or oil level too high
  • Pre-HO2S or MAFS contamination
  • Fuel system
  • EVAP system
  • Faulty sensor signals

How to Fix Code P1166 2002 HYUNDAI SANTA FE?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

  • Engine light on (or engine service warning light soon)

P1166 2002 HYUNDAI SANTA FE Meaning

The Lambda closed-loop control system is included in the engine control system. The control system regulates the upstream lambda with the HO2S signal. Rich mixtures generate high concentrations of CO, H2, and HC. Lean mixtures generate high concentrations of NOx and free oxygen.

If the lambda controller reaches the maximum or minimum threshold, feedback control is no longer possible and emissions will be increased. The ECM sets DTC P1166 if no proportional fuel adaptation occurs for a defined time after the lambda controller reaches its minimum or maximum threshold.

P1166 2002 NISSAN SENTRA – Heated Oxygen Sensor 2 Minimum Voltage Monitoring, Bank 2

P1166 2002 NISSAN SENTRA Possible Causes

  • Faulty Heated Oxygen Sensor (O2) 2 (rear)
  • Intake air leaks
  • Heated Oxygen Sensor (O2) 2 (rear) harness is open or shorted
  • Poor electrical connection in Heated Oxygen Sensor (O2) 2 (rear) circuit
  • Inappropriate fuel pressure
  • Faulty fuel injectors

How to Fix Code P1166 2002 NISSAN SENTRA?

Start by checking the “Possible Causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Technical Notes

Replacing the O2 sensor 2 usually resolves the issue

Possible Symptoms

  • Engine Light On (or Service Engine Soon Warning Light)
  • High fuel consumption
  • Excessive smoke from exhaust

P1166 2002 NISSAN SENTRA Meaning

The Heated Oxygen Sensor 2 (HO2S) (rear O2 sensor), located after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gases on each bank. For optimal catalyst operation, the air-fuel mixture (air-fuel ratio) must be maintained close to the ideal stoichiometric ratio. The HO2S output voltage changes abruptly near the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gases. If oxygen in the exhaust gases increases, the air-fuel ratio becomes lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If oxygen in the exhaust gases decreases, the air-fuel ratio becomes rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

P1166 2004 INFINITI G35 – Heated Oxygen Sensor 2 Minimum Voltage Monitoring, Bank 2

P1166 2004 INFINITI G35 Possible Causes

  • Faulty Heated Oxygen Sensor (O2) 2 (rear)
  • Intake air leaks
  • Heated Oxygen Sensor (O2) 2 (rear) harness is open or shorted
  • Poor electrical connection in the Heated Oxygen Sensor (O2) 2 (rear) circuit
  • Inappropriate fuel pressure
  • Faulty fuel injectors

How to Fix Code P1166 2004 INFINITI G35?

Start by checking the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Technical Notes

Replacing the O2 sensor 2 usually resolves the issue

Possible Symptoms

  • Engine Light On (or Service Engine Soon Warning Light)
  • High fuel consumption
  • Excessive exhaust smoke

P1166 2004 INFINITI G35 Meaning

The Heated Oxygen Sensor 2 (HO2S) (rear O2 sensor), located after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gases on each bank. For optimal catalyst operation, the air-fuel mixture (air-fuel ratio) must be maintained close to the ideal stoichiometric ratio. The HO2S output voltage changes abruptly near the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to the oxygen in the exhaust gases. If the oxygen in the exhaust gases increases, the air-fuel ratio becomes lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gases decreases, the air-fuel ratio becomes rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

P1166 2004 NISSAN MAXIMA – Heated Oxygen Sensor 2 Minimum Voltage Monitoring, Bank 2

P1166 2004 NISSAN MAXIMA Possible Causes

  • Faulty Heated Oxygen Sensor (O2) 2 (rear)
  • Intake air leaks
  • Heated Oxygen Sensor (O2) 2 (rear) harness is open or shorted
  • Poor electrical connection in the Heated Oxygen Sensor (O2) 2 (rear) circuit
  • Inappropriate fuel pressure
  • Faulty fuel injectors

How to Fix Code P1166 2004 NISSAN MAXIMA?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Technical Notes

Replacing the O2 sensor 2 usually resolves the issue

Possible Symptoms

  • Engine light on (or service engine soon warning light)
  • High fuel consumption
  • Excessive exhaust smoke

P1166 2004 NISSAN MAXIMA Meaning

The Heated Oxygen Sensor 2 (HO2S) (rear O2 sensor), located after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gases on each bank. For optimal catalyst operation, the air-fuel mixture (air-fuel ratio) must be maintained close to the ideal stoichiometric ratio. The HO2S output voltage changes abruptly near the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to the oxygen in the exhaust gases. If the oxygen in the exhaust gases increases, the air-fuel ratio becomes lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gases decreases, the air-fuel ratio becomes rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

P1166 2005 INFINITI G35 – Heated Oxygen Sensor 2 Minimum Voltage Monitoring, Bank 2

P1166 2005 INFINITI G35 Possible Causes

  • Faulty Heated Oxygen Sensor (O2) 2 (rear)
  • Intake air leaks
  • Heated Oxygen Sensor (O2) 2 (rear) harness is open or shorted
  • Poor electrical connection in the Heated Oxygen Sensor (O2) 2 (rear) circuit
  • Inappropriate fuel pressure
  • Faulty fuel injectors

How to Fix Code P1166 2005 INFINITI G35?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Technical Notes

Replacing the O2 sensor 2 usually resolves the issue

Possible Symptoms

  • Engine light on (or service engine soon warning light)
  • High fuel consumption
  • Excessive smoke from exhaust

P1166 2005 INFINITI G35 Meaning

The Heated Oxygen Sensor 2 (HO2S) (rear O2 sensor), located after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gases on each bank. For optimal catalyst operation, the air-fuel mixture (air-fuel ratio) must be maintained close to the ideal stoichiometric ratio. The HO2S output voltage changes abruptly near the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to the oxygen in the exhaust gases. If the oxygen in the exhaust gases increases, the air-fuel ratio becomes lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gases decreases, the air-fuel ratio becomes rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

P1166 ACURA – Malfunction in Heater Circuit of Air/Fuel Ratio Sensor 1

P1166 ACURA Possible Causes

  • Faulty Air/Fuel Ratio Sensor 1
  • Air/Fuel Ratio Sensor 1 harness is open or shorted
  • Poor electrical connection in the Air/Fuel Ratio Sensor 1 circuit

How to Fix P1166 ACURA Code?

Start by checking the “Possible Causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

When is the Code Detected?

A malfunction is detected and the code is stored if the heater element is not activated or if the voltage at the Engine Control Module (ECM) terminals is a specified value or less for at least a specified period of time when power is supplied to the A/F sensor heater (Sensor 1).

Possible Symptoms

  • Check Engine Light On (or Service Engine Soon Warning Light)

P1166 ACURA Meaning

The Air/Fuel Ratio (A/F) Sensor 1 is installed in the exhaust system and detects the oxygen concentration in the exhaust gases. The A/F sensor sends the output voltage to the Engine Control Module (ECM). A heating element for the sensor element is built into the A/F sensor (Sensor 1). It is activated and heats the sensor to stabilize and speed up the detection of oxygen concentration by controlling the current flowing through the heater. The current increase stabilizes when the voltage applied to the element electrode reaches a certain range because the amount of oxygen that passes through the diffusion layer is limited. The current amperage is proportional to the oxygen concentration in the exhaust gases, so the air/fuel ratio is detected by measuring the current amperage. The ECM compares a preset target air/fuel ratio with the detected air/fuel ratio and controls the fuel injection timing.
If the A/F sensor (Sensor 1) voltage is low, the air/fuel ratio is lean and the ECM uses A/F feedback control to issue a Rich command. If the A/F sensor (Sensor 1) voltage is high, the air/fuel ratio is rich and the ECM uses A/F feedback control to issue a Lean command.

P1166 AUDI – Bank 1 Long Term Fuel Trim Range 2 Rich Upper Limit Exceeded

P1166 AUDI Possible Causes

  • High fuel pressure – Blocked return system or faulty pressure regulator
  • Faulty fuel injector
  • EVAP purge solenoid stuck open
  • Misfiring cylinder
  • Fix other codes first

How to fix P1166 AUDI code?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

  • Engine light on (or engine service warning light soon)

P1166 AUDI Meaning

Bank 1 Fuel Balance Long Term Range 2 Upper Rich Limits Exceeded is the generic description for Audi P1166 code, but the manufacturer may have a different description for your vehicle model and year. Currently, we don’t have more information about the Audi P1166 OBDII code.

P1166 HONDA – Malfunction in Heater Circuit of Air/Fuel Ratio Sensor 1

P1166 HONDA Possible Causes

  • Faulty Air/Fuel Ratio Sensor 1
  • Air/Fuel Ratio Sensor 1 harness is open or shorted
  • Poor electrical connection in the Air/Fuel Ratio Sensor 1 circuit

How to Fix Code P1166 HONDA?

Start by checking the “Possible Causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Technical Notes

When is the Code Detected?

If the heater element is not activated or if the voltage at the Engine Control Module (ECM) terminals is a specified value or less for at least a specified period of time when power is supplied to the A/F sensor heater (Sensor 1), a malfunction is detected and the code is stored.

Possible Symptoms

  • Engine Light On (or Service Engine Soon Warning Light)

P1166 HONDA Meaning

The Air/Fuel Ratio (A/F) Sensor 1 is installed in the exhaust system and detects the oxygen concentration in the exhaust gases. The A/F sensor sends the output voltage to the Engine Control Module (ECM). A heating element for the sensor element is built into the A/F sensor (Sensor 1). It is activated and heats the sensor to stabilize and speed up the detection of oxygen concentration by controlling the current flowing through the heater. The current increase stabilizes when the voltage applied to the element electrode reaches a certain range because the amount of oxygen that is transported through the diffusion layer is limited. The current amperage is proportional to the oxygen concentration in the exhaust gases, so the air/fuel ratio is detected by measuring the current amperage. The ECM compares a defined target air/fuel ratio with the detected air/fuel ratio and controls the fuel injection timing.
If the A/F sensor (Sensor 1) voltage is low, the air/fuel ratio is lean and the ECM uses A/F feedback control to issue a Rich command. If the A/F sensor (Sensor 1) voltage is high, the air/fuel ratio is rich and the ECM uses A/F feedback control to issue a Lean command.

P1166 HYUNDAI – O2 Sensor System Lambda Controller at Limit, Bank 1

P1166 HYUNDAI Possible Causes

  • Air leak or restriction in the intake or exhaust system
  • Dirty engine oil or oil level too high
  • Contamination before HO2S or MAFS
  • Fuel system
  • EVAP system
  • Faulty sensor signals

How to Fix Code P1166 HYUNDAI?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Possible Symptoms

  • Engine light on (or engine warning light soon to be active)

P1166 HYUNDAI Meaning

The closed-loop Lambda control system is included in the engine control system. The control system regulates the upstream lambda with the HO2S signal. Rich mixtures generate high concentrations of CO, H2, and HC. Lean mixtures generate high concentrations of NOx and free oxygen.
If the lambda controller reaches the maximum or minimum threshold, feedback control is no longer possible and emissions will be increased. The ECM sets the DTC P1166 if no proportional fuel adaptation occurs for a defined time after the lambda controller reaches its minimum or maximum threshold.

P1166 INFINITI – Heated Oxygen Sensor 2 Minimum Voltage Monitoring, Bank 2

P1166 INFINITI Possible Causes

  • Faulty Heated Oxygen Sensor (O2) 2 (rear)
  • Intake air leaks
  • Heated Oxygen Sensor (O2) 2 (rear) harness is open or shorted
  • Poor electrical connection in the Heated Oxygen Sensor (O2) 2 (rear) circuit
  • Inappropriate fuel pressure
  • Faulty fuel injectors

How to Fix Code P1166 INFINITI?

Start by checking the “possible causes” listed above. Visually inspect the corresponding wiring harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.

Technical Notes

Replacing the O2 sensor 2 usually resolves the issue

Possible Symptoms

  • Engine light on (or service engine soon warning light)
  • High fuel consumption
  • Excessive smoke from exhaust

P1166 INFINITI Meaning

The Heated Oxygen Sensor 2 (HO2S) (rear O2 sensor), located after the three-way catalyst (manifold), monitors the oxygen level in the exhaust gases on each bank. For optimal catalyst operation, the air-fuel mixture (air-fuel ratio) must be maintained close to the ideal stoichiometric ratio. The HO2S output voltage changes abruptly near the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gases. If oxygen in the exhaust gases increases, the air-fuel ratio becomes lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If oxygen in the exhaust gases decreases, the air-fuel ratio becomes rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.