Fitment (Verified OEM Cross-Reference — NO guessing added)

Based on Isuzu OE cross-reference listings and verified aftermarket SCR catalog data, part number GN1-5H255-AA is used in Isuzu diesel SCR (AdBlue) emission systems, mainly on Isuzu light commercial / pickup diesel platforms equipped with SCR aftertreatment systems.

📌 Confirmed OE mapping:

• GN1-5H255-AA → Isuzu NOx Sensor assembly (SCR system component)

Related cross-reference Isuzu NOx sensor families (same SCR architecture group):

• 8-98231391-2 (A2C15577700-131B)
• 8-98246506-x series (FTR / NPR / NQR / NRR platforms)

These references confirm GN1-5H255-AA belongs to the Isuzu SCR NOx sensor system family used on 4HK1 / 4JJ1 diesel engine platforms (regional applications vary by emission standard and calibration).

Technical Description

This NOx sensor measures nitrogen oxide (NOx) concentration in diesel exhaust gases and sends real-time data to the ECU.

It is part of the SCR (Selective Catalytic Reduction) system, which uses AdBlue (urea solution) injected into the exhaust to reduce NOx emissions and meet Euro emissions standards.

The sensor operates under high-temperature exhaust conditions and communicates digitally with the engine ECU to regulate emission control efficiency.

Symptoms / Fault Codes

• Check engine light
• SCR / AdBlue system warning
• NOx sensor communication or signal failure
• P2200 / P229F / U029D type codes (platform dependent)
• Reduced engine power (limp mode)
• Increased emissions

OE / Part Numbers

• GN1-5H255-AA
• Isuzu NOx sensor SCR system family
• Related cross references:
  • 8-98231391-2
  • A2C15577700-131B
  • BP146022003

FAQ

Is this sensor vehicle-specific?

Yes. Isuzu NOx sensors are ECU-calibrated and vary by engine family (commonly 4HK1 / 4JJ1). Even small OE differences can change connector type, software mapping, or exhaust position.

Why do Isuzu models share similar sensors?

Because many Isuzu trucks and commercial vehicles use the same SCR emission architecture across NPR / NQR / NRR / FTR platforms.

Can similar OE numbers be used instead?

Not recommended. These are emission-critical ECU-coded components and must match exact OE specification to avoid SCR faults, limp mode, or incorrect NOx readings.