AutoCodes – Generic – P2277

P2277 Code - O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 3

Quick Answer

The downstream heated oxygen sensor (HO2S) is forced rich and lean and monitored by the Powertrain Control Module (PCM). Common causes include Faulty O2 Sensor Bank 2 Sensor 3, Exhaust leaks, O2 Sensor Bank 2 Sensor 3 harness is open or shorted. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P2277 indicates O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 3.
Common causes: Common causes include Faulty O2 Sensor Bank 2 Sensor 3, Exhaust leaks, O2 Sensor Bank 2 Sensor 3 harness is open or shorted.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 8,409

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P2277 Description

The downstream heated oxygen sensor (HO2S) is forced rich and lean and monitored by the Powertrain Control Module (PCM). The test fails if the PCM does not detect the output of the HO2S in a calibrated amount of time.

OBDII Code P2277 - O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 3 - AutoCodes.com — P2277 Code - O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 3

What does this mean?

What are the Possible Causes of the DTC P2277?

Faulty O2 Sensor Bank 2 Sensor 3
Exhaust leaks
O2 Sensor Bank 2 Sensor 3 harness is open or shorted
O2 Sensor Bank 2 Sensor 3 circuit poor electrical connection

How to Fix the DTC P2277?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2277 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

P2277 Dodge — O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 3

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.