LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chrysler >> 2009 >> 300 LX >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> DTCS P0121 To P0172 >> P0131-O2 Sensor 1/1 Circuit Low >> Possible Causes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Possible Causes

Possible Causes 
(K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO GROUND
(K902) O2 RETURN (UP) CIRCUIT SHORTED TO GROUND
(K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO THE (K902) O2 RETURN (UP) CIRCUIT
1/1 OXYGEN SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. See  DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure  .