← Back to list

OBD2 P0157 Fault in 2000 Chevrolet Silverado 5.3L 4x4 Z71 with 288,000 km

Model: Silverado Fault Code: P0157 Posted: 2007-09-14 18:33

I own a 2000 Chevrolet Silverado 5.3L V8 4x4 Z71 with 288,000 kilometers on the odometer. Previously, I experienced OBD2 fault code P0161 (Oxygen Sensor Bank 2, Sensor 2), which I resolved by replacing the sensor. After that, a new code appeared: P0157 — indicating low voltage signal from the same oxygen sensor (Bank 2, Sensor 2). I reinstalled the sensor with proper connection to ensure correct wiring, but the code persists. The truck continues to drive normally and remains in closed-loop operation. Despite this, I'm concerned about what could be causing P0157. Could it be a faulty sensor, an exhaust leak near the catalytic converter, or an issue with the wiring harness? Any insights would be greatly appreciated.

Related fault codes
P0157
Comments (5)
Anonymous 2007-09-15 07:46

Did you install a plug-in O2 sensor or use a cut-and-splice method? Is there a fuse labeled 'O2' in the vehicle's electrical system?

Anonymous 2007-09-15 09:27

I used a plug-in style sensor. I didn't consider checking for an O2-related fuse initially, though I assumed the engine was operating in closed-loop mode due to normal driving behavior. I'll now inspect the fuse box. Since only one side (post-catalytic converter) of the oxygen sensor is affected, could a failing catalytic converter or an exhaust leak near it be responsible? A lower voltage reading suggests higher oxygen content, which might point to a hole in the converter or exhaust pipe close to the catalytic converter.

Anonymous 2007-09-15 12:12

An exhaust leak is possible and should not be ruled out — especially near the sensor location.

Anonymous 2007-09-16 00:12

Hi! It's also possible that your catalytic converter is failing, particularly given the high mileage. Check both the catalytic converter and the exhaust pipe immediately adjacent to it for potential leaks or damage.

Anonymous 2007-09-17 14:05

No, the issue isn't likely with the catalytic converter. P0157 specifically means the Powertrain Control Module (PCM) detected a signal voltage below 0.25 volts from the O2 sensor for an extended period. The most probable causes are exhaust leaks near the sensor or damaged wiring harness. A faulty sensor is also possible, but a thorough inspection of the wiring and surrounding components is recommended before concluding.