1997 Chrysler LHS P0140 OBD2 Code: Causes, Symptoms, and Fixes
I own a 1997 Chrysler LHS with 18,000 miles. Recently, my check engine light came on, and an OBD2 scan tool detected a persistent P0140 code. The downstream oxygen sensor reading remains at center (50% oxygen level) during operation. I replaced all four oxygen sensors as the vehicle was nearing 18,000 miles. After clearing the code with the scanner, the check engine light stays off until I reach speeds of 50 mph or higher. Despite this, the downstream O2 sensor reading remains in the center range. What does a P0140 code specifically mean for my 1997 Chrysler LHS? Are there any other potential causes besides faulty sensors?
I have a 1997 Chrysler LHS with 18,000 miles. The check engine light came on recently, and my OBD2 scanner detected code P0140. Since the vehicle has only 18,000 miles, I replaced all four oxygen sensors. After clearing the code using a scan tool, the warning light stays off until I drive over 50 mph. The downstream O2 sensor reading remains at center (50% oxygen). This behavior suggests an ongoing issue with the downstream oxygen sensor or its associated wiring. Could there be another underlying cause? Any recommendations for troubleshooting?