P0140 on Chrysler 300
Factory diagnostic protocol and troubleshooting wire for fault code P0140 specifically for the Chrysler 300 (2020–2025, 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)).
1. Symptoms of P0140 on Chrysler 300
When the Engine Control Module (ECM/PCM) on your Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)) logs fault code P0140, drivers commonly observe:
2. Most Likely Causes on Chrysler 300
Historical warranty claims and technical repair bulletins for Chrysler 300 point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Chrysler 300
Inspect harness connector under vehicle floor pan. Verify plug is firmly seated and weather seal is intact. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Check for 12V heater power and ground at connector with ignition ON. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Remove and replace the downstream oxygen sensor with an OEM-spec part. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Clear code and verify sensor activity returns on live telemetry. on the Chrysler 300 equipped with 3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8).
Equipment for Diagnosing Chrysler 300 (P0140)
Chrysler 300 OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for Chrysler 300.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on Chrysler 300
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Chrysler 300:
4. Chrysler 300 P0140 FAQs
What causes code P0140 to trigger on a Chrysler 300?
On the Chrysler 300 (3.6L Pentastar V6 (292HP) / 5.7L / 6.4L 392 HEMI V8 (485HP SRT8)), P0140 is most frequently caused by Completely dead downstream O2 sensor or Disconnected sensor harness plug under car.
Where is the OBD-II port located on my Chrysler 300?
On the Chrysler 300, the 16-pin DLC diagnostic connector is located Under driver side dash near left knee panel. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Chrysler 300 with code P0140?
Yes, safe for normal driving without risk of breakdown. Given that P0140 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.

