AutoCodes – Generic – P1146

P1146 Code - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1

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: P1146 indicates Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1.
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 13,139

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 May 01, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P1146 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 P1146 - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1 - AutoCodes.com — P1146 Code - Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1

What does this mean?

What are the Possible Causes of the DTC P1146?

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 P1146?

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 P1146 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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Information for Specific Makes

P1146 Audi — Mass Air Flow Sensor Supply Voltage
P1146 Hyundai — Idle Co Potentiometer
P1146 Infiniti — Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1
P1146 Nissan — Heated Oxygen Sensor 2 Minimum Voltage Monitoring Bank 1
P1146 Subaru — Pressure Sensor Circuit Range/Performance Problem High Input
P1146 Volkswagen — Mass Air Flow Sensor Supply Voltage

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.