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

P1166 KIA 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 KIA?

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 on)

P1166 KIA 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 DTC P1166 if no proportional fuel adaptation occurs for a defined time after the lambda controller reaches its minimum or maximum threshold.

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

P1166 NISSAN 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 NISSAN?

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

P1166 NISSAN 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 SUZUKI – Low Voltage in HO2S Circuit During Power Enrichment Sensor 1

P1166 SUZUKI – Diagnosis and Solutions 🚗

🛠 Possible Causes

  • 🚨 Faulty Heated Oxygen Sensor 1 (HO2S)
  • 🔌 HO2S 1 Sensor Wiring Harness Open or Short Circuit
  • ⚠️ Poor Electrical Connection in HO2S 1 Sensor Circuit

🔧 How to Fix P1166 SUZUKI Code

  1. 🔍 Check the causes listed above.
  2. 📎 Visually inspect the wiring harness and connectors associated with HO2S 1 sensor.
  3. ⚡ Look for damage: broken, bent, corroded, or improperly secured pins.
  4. 🔌 Test the Heated Oxygen Sensor 1 (voltage/resistance measurement according to Suzuki specifications).

⚠️ Possible Symptoms

  • 📛 Check Engine Light On (or “Service Engine Soon” message).

📖 Meaning of P1166 SUZUKI Code

The Engine Control Module (ECM) detects an abnormally low voltage in the Heated Oxygen Sensor 1 (HO2S) circuit during the air-fuel mixture enrichment phase.

  • 📍 Note: This code is specific to Suzuki. The description may vary depending on the vehicle model and year.

✅ Tip:

  • Consult Suzuki technical bulletins or a model-specific repair manual for accurate data.
  • If the sensor and electrical circuit are functional, check for underlying issues (vacuum leaks, injection problems, etc.).

🚨 Warning: This code may require Suzuki expertise for thorough diagnosis if basic checks do not resolve the issue.

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

P1166 VOLKSWAGEN 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 Volkswagen P1166 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

  • Check Engine Light on (or Service Engine Soon warning light)

P1166 VOLKSWAGEN Meaning

Bank 1 Long Term Fuel Trim Range 2 Rich Upper Limits Exceeded is the generic description for Volkswagen code P1166, but the manufacturer may have a different description for your vehicle model and year. Currently, we have no further information about Volkswagen OBDII code P1166.

P1167 – Heated Oxygen Sensor Rear 2 Maximum Voltage Monitoring, Bank 2

P1167 Possible Causes

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

How is Code P1167 Repaired?

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 Service Engine Soon Warning Light)

P1167 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 heater 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 channeled 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 set 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.

P1167 1996 HONDA CIVIC – Air/Fuel Ratio Sensor Heater System Malfunction 1

P1167 1996 HONDA CIVIC Possible Causes

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

How to Fix Code P1167 1996 HONDA CIVIC?

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)

P1167 1996 HONDA CIVIC 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 routed 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.

P1167 2004 INFINITI G35 – Rear Heated Oxygen Sensor 2 Maximum Voltage Monitoring, Bank 2

P1167 2004 INFINITI G35 Possible Causes

  • Faulty Heated Oxygen Sensor Rear, Bank 2
  • Heated Oxygen Sensor Rear, Bank 2 Harness is open or shorted
  • Heated Oxygen Sensor Rear, Bank 2 circuit poor electrical connection
  • Fuel Pressure
  • Fuel Injectors
  • Intake Air Leaks

How to Fix Code P1167 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 rear oxygen sensor (O2) usually solves the problem

When is the Code Detected?

The P1167 code is set when the maximum sensor voltage is not reached at the specified voltage.

Possible Symptoms

  • Engine Light On (or Service Engine Soon Warning Light)
  • Possible High Fuel Consumption
  • Possible Excessive Smoke from Exhaust

P1167 2004 INFINITI G35 Meaning

The Heated Oxygen Sensor 2 (rear), after Three-Way Catalyst, monitors the oxygen level in the exhaust gas on each bank. Even if the switching characteristics of the Heated Oxygen Sensor 1 (front) are shifted, the air-fuel ratio is controlled to stoichiometric by the signal from Heated Oxygen Sensor 2. This sensor is a zirconia ceramic type. Zirconia generates a voltage from about 1 V under richer conditions to 0 V under leaner conditions. Under normal conditions, the Heated Oxygen Sensor 2 is not used for engine control operation.

P1167 2004 NISSAN ALTIMA SEDAN – Rear Heated Oxygen Sensor 2 Maximum Voltage Monitoring, Bank 2

P1167 2004 NISSAN ALTIMA SEDAN Possible Causes

  • Faulty heated rear oxygen sensor, bank 2
  • Bank 2 heated rear oxygen sensor harness is open or shorted
  • Poor electrical connection in the heated rear oxygen sensor circuit, bank 2
  • Fuel pressure
  • Injectors
  • Intake air leaks

How to Fix Code P1167 2004 NISSAN ALTIMA SEDAN?

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 rear oxygen (O2) sensor usually resolves the issue

When is the Code Detected?

The P1167 code is triggered when the maximum sensor voltage is not reached at the specified voltage.

Possible Symptoms

  • Engine light on (or service engine soon warning light)
  • Possible high fuel consumption
  • Possible excessive smoke from exhaust

P1167 2004 NISSAN ALTIMA SEDAN Meaning

The heated oxygen sensor 2 (rear), after three-way catalyst, monitors the oxygen level in the exhaust gases on each bank. Even if the switching characteristics of heated oxygen sensor 1 (front) are shifted, the air-fuel ratio is controlled to stoichiometric by the signal from heated oxygen sensor 2. This sensor is made of zirconia ceramic. Zirconia generates a voltage from about 1 V in richer conditions to 0 V in leaner conditions. Under normal conditions, heated oxygen sensor 2 is not used for engine control operation.

P1167 ACURA – Malfunction of Air/Fuel Ratio Sensor 1 Heater System

P1167 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 P1167 ACURA Code?

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.

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)

P1167 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 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 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.

P1167 AUDI – Mass Air Flow Sensor 2 Signal Not Plausible

P1167 AUDI Possible Causes

  • Faulty mass air flow (MAF)
  • Mass air flow (MAF) harness is open or shorted
  • Poor electrical connection in mass air flow (MAF) circuit

How to Fix Code P1167 AUDI?

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 service engine soon warning light)

P1167 AUDI Meaning

Implausible Signal from Mass Air Flow Sensor 2 is the generic description for Audi P1167 code, but the manufacturer may have a different description for your model and vehicle year. Currently, we don’t have more information about the Audi P1167 OBDII code.