FITMENT:
Compatible with Caterpillar Inc. off-highway machinery equipped with SCR emission systems, including excavators, generators, scrapers, compactors, and industrial engines.

OEM reference number: 539-0118.
Used in diesel exhaust aftertreatment system for NOx monitoring (DEF/AdBlue SCR system).
This is a complete NOx emissions sensor assembly (probe + control module + harness).
Installed in exhaust system (typically tailpipe outlet / SCR downstream position depending on machine configuration).

Fitment must be confirmed by OEM part number and machine serial number before installation.

FAQ:

Q1: What machines does this fit?
A1: It is used on multiple CAT off-highway platforms such as excavators, generators, scrapers, compactors, and marine/industrial engines depending on emissions configuration.

Q2: Where is this NOx sensor installed?
A2: It is typically installed in the SCR system outlet (tailpipe downstream) to measure final NOx emissions after treatment.

Q3: What does this sensor do?
A3: It measures real-time NOx and oxygen levels in exhaust and sends data to the engine control system for SCR dosing adjustment.

Q4: What are common failure symptoms?
A4: SCR warning light, derate mode, NOx sensor fault codes, incorrect AdBlue dosing, or reduced engine power.

Q5: Is this plug-and-play?
A5: In most cases yes, but some CAT machines require calibration or diagnostic reset after replacement.