GM Genuine Parts AFS138 Heated Oxygen Sensor (19178961) – OE Quality, Fits 1999–2002 GM Vehicles

Overview

GM Genuine Parts AFS138 heated oxygen sensor (19178961) is an authentic OE replacement purposefully designed for GM vehicles. This sensor monitors the oxygen content in exhaust gases as they exit the engine, providing feedback to the engine control module (ECM). By delivering real-time data, it helps the ECM adjust the air–fuel ratio toward the near-ideal balance of about 14.7:1. While individual results can vary with driving conditions and vehicle history, a properly functioning sensor can contribute to steadier idle, smoother acceleration, and more consistent performance across a wide range of temperatures and loads.

Key benefits and what to expect

• Detects oxygen levels in exhaust to support efficient combustion and potentially cleaner emissions
• GM-recommended replacement part that mirrors the original factory component for your GM vehicle
• Offers the reliability and durability associated with GM OE parts
• Manufactured to GM OE specifications for precise fit, form, and function
• Connector Gender: Female, simplifying installation and connection
• Fits multiple GM models, including Chevrolet, Cadillac, and GMC trucks and SUVs

Compatibility and installation basics

This sensor is designed to align with GM’s original specifications, ensuring compatibility with the listed models. The female connector orientation supports a secure electrical connection and reliable operation after replacement. During installation, follow standard safety steps: disconnect the battery, allow the exhaust system to cool, and consult your vehicle’s service manual for torque guidelines and any GM-recommended lubrication or anti-seize processes. The goal is a clean, snug interface that resists future loosening and corrosion while preserving sensor performance over time.

Real-world use cases

In everyday driving, a well-functioning O2 sensor can contribute to smoother starts, steadier cruising, and consistent throttle response. It may help the ECM manage the air–fuel mixture more effectively across varying loads, which can translate to steadier engine behavior during city stops and highway cruising alike. Remember, actual outcomes depend on vehicle condition, sensor age, and driving habits.

What’s in the detail

• OE-grade construction and material quality designed to endure heat and vibration
• GM OE specification adherence ensures proper fit and function
• Female connector design supports straightforward wiring hook-up
• Model coverage includes Chevrolet Avalanche 1500, Tahoe, Suburban 1500, Silverado 1500 (1999–2002), Silverado 2500 (1999–2000), Cadillac Escalade (2002), GMC Yukon/Yukon XL 1500, Sierra 1500 (1999–2002), and Sierra 2500 (1999–2000)