GPD 1815168 Downstream Nitrogen Oxide NOx Sensor Direct Fit

The GPD 1815168 is a direct-fit aftermarket downstream Nitrogen Oxide (NOx) sensor designed as a reliable replacement for failed or degraded OEM units. NOx sensors are a critical component of the exhaust aftertreatment system, monitoring nitrogen oxide (NO and NO₂) concentrations in the exhaust stream to ensure proper emissions control and engine management.

This sensor is positioned downstream — after the SCR (Selective Catalytic Reduction) unit — where it measures NOx levels post-DEF treatment. The ECU uses this data to evaluate SCR conversion efficiency and determine whether additional DEF injection is required. A failed downstream NOx sensor can trigger fault codes, illuminate the check engine light, and cause engine derate conditions.

Key Features:

• Direct Fit — engineered to match OEM connector, thread pitch, and mounting location for hassle-free installation
• Downstream position — measures NOx output after the SCR catalytic converter
• Monitors NO and NO₂ concentrations in real time for accurate emissions feedback
• Supports proper SCR system operation and DEF consumption management
• Built to withstand high-temperature and high-vibration exhaust system environments
• Helps prevent engine derate and keep the vehicle in emissions compliance

GPD (Global Parts Distributors) has been a trusted name in aftermarket automotive and heavy-duty parts since 1974, offering quality engine management sensors at competitive prices. The GPD 1815168 is the right choice for a dependable, cost-effective NOx sensor replacement.