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P1166 2005 Infiniti G35 Code - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 2

Quick Answer

The Heated Oxygen Sensor 2 (HO2S) (Rear O2 Sensor), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty heated oxygen (O2) sensor 2 (rear), Intake air leaks, Heated oxygen (O2) sensor 2 (rear) harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1166 2005 Infiniti G35 indicates Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 2.
Common causes: Common causes include Faulty heated oxygen (O2) sensor 2 (rear), Intake air leaks, Heated oxygen (O2) sensor 2 (rear) harness is open or shorted.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 3,061

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 01, 2024

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P1166 2005 Infiniti G35 Description

The Heated Oxygen Sensor 2 (HO2S) (Rear O2 Sensor), after 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 be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of 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 gas. If the oxygen in the exhaust gas 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 gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

OBDII Code P1166 2005 Infiniti G35 - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 2 - AutoCodes.com — P1166 2005 Infiniti G35 Code - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 2

What does this mean?

What are the Possible Causes of the DTC P1166 2005 Infiniti G35?

Faulty heated oxygen (O2) sensor 2 (rear)
Intake air leaks
Heated oxygen (O2) sensor 2 (rear) harness is open or shorted
Heated oxygen (O2) sensor 2 (rear) circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors

How to Fix the DTC P1166 2005 Infiniti G35?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

Replacing the O2 Sensor 2 usually takes care of the problem

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1166 2005 Infiniti G35 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1166 2005 Infiniti G35 Code

What does the OBDII code P1166 mean for a 2005 Infiniti G35?

P1166 indicates that the heated oxygen sensor (HO2S) 2 in Bank 2 is not producing the minimum required voltage, suggesting a potential issue with the sensor or its circuit.

What symptoms might I experience with the P1166 code?

Common symptoms include poor fuel economy, rough idling, increased emissions, and the check engine light being illuminated.

What could cause the P1166 code to trigger?

Possible causes include a faulty oxygen sensor, wiring issues (such as damaged or corroded connectors), exhaust leaks, or problems with the engine's fuel delivery system.

Can I drive my car with the P1166 code?

While it may be possible to drive the vehicle, it is not recommended as it can lead to further engine performance issues and increased emissions.

How can I diagnose the issue related to the P1166 code?

Start by visually inspecting the wiring and connectors of the HO2S, then test the sensor's voltage output using a multimeter. If necessary, check for exhaust leaks and other related components.

What is the typical repair for a P1166 code?

The most common repair is replacing the faulty heated oxygen sensor in Bank 2. However, if wiring issues are found, repairing or replacing damaged wiring may be required.

After fixing the issue, will the check engine light turn off automatically?

Yes, once the problem is resolved, the check engine light should turn off after a few driving cycles. You can also clear the code with an OBDII scanner.

What is the location of the Bank 2 heated oxygen sensor in a 2005 Infiniti G35?

The Bank 2 heated oxygen sensor is typically located after the catalytic converter on the exhaust system, on the side of the engine opposite to Bank 1.

Can a dirty or clogged air filter affect the P1166 code?

Yes, a dirty air filter can disrupt the air-fuel mixture, potentially leading to issues with the oxygen sensor readings and triggering the P1166 code.