Caterpillar Fault Code

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3216-20

Regen Inop

System

Emissions

Symptom

Regen Inop

Diagnosis & fix steps

LOGIC: Intake NOx Sensor Drifted. ACTION: Clean sensor probe of soot. Perform a "NOx Sensor Verification" test in ET.

Red Seal field insights

Logic: The sensor is reading "stale" or static data compared to the outlet sensor.

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