P0157 Code Chevy Silverado

P0157 code on Chevy Silverado dashboard indicates that the O2 sensor is not working properly. The warning code can hurt your bank if you ignore P0157 error code on Chevy Silverado. P0157 error code show on dashboard due to worn-out sensor wiring, exhaust leak or PCM failure.

Though this trouble code doesn’t make the car risky to drive, it can damage the sensor, catalytic converter or engine if you ignore it for a long time.

What Does P0157 Code Chevy Silverado Mean?

P0157 is defined as an oxygen sensor circuit low voltage problem. When computer detects a low voltage signal of downstream oxygen sensor for a long time, it activates P0157 error code.

PCM can activate P0157 error code if the voltage of oxygen sensor remains under 400 millivolts for over 2 minutes. Downstream oxygen sensors monitor catalytic converter’s efficiency by checking oxygen in exhaust gas and sending data to PCM.

When PCM detects significant differences between upstream and downstream O2 sensors, it considers the catalytic converter as a failure. PCM can also set the P0157 trouble code if rear oxygen sensor stays in lean phase for a long time.

Also Read: P003A Code

Major Causes of P0157 Chevy Silverado

Chevy Silverado can cause p0157 trouble code mostly due to these reasons:

1. Defective Oxygen Sensor

Rear oxygen sensor is placed in exhaust system near catalytic converters. It fails due to poor insulation, faulty wiring, clogged fuel injectors, or other electrical problems. When rear O2 sensor fails, PCM doesn’t get proper feedback about the condition of catalytic converter and sets P0157 code.

Defective Oxygen Sensor

2. Lean Running Condition

Engine can cause lean running due to lack of fuel or excess air in the tank. Lean air mixture affects catalytic converter as it acts as a capacitor for oxygen which can trigger the error code. This condition can cause a knocking sound in engine, trouble down the line and engine failure.

Lean Running Condition

3. Faulty Sensor Wiring

Oxygen sensors can also malfunction due to worn-out wires. Hence rear oxygen sensor can make a lower voltage than specific threshold and trigger the error code. Some common symptoms of faulty O2 wiring are blinking check engine light, rough idling, engine overheating, black smoke from exhaust pipe and malfunction of catalytic converter.

4. Exhaust Leaks

Exhaust systems can leak due to high exhaust temperature rust and corrosion in their parts. O2 sensor is located in the exhaust system. So exhaust leak directly affects the oxygen sensor’s reading and it can set P0157 code.

Exhaust Leaks

5. PCM Failure

PCM tests rear oxygen sensors for proper voltage threshold and makes sure it can recognize lean conditions. However, the PCM can malfunction due to software concerns, overload shorted circuits, or power surges. A faulty PCM might not be able to receive data from sensors and can set an error code.

PCM Failure

How To Diagnose P0157 Code On Chevy Silverado?

After discovering P0157 error code, physically check these components to understand their condition. This will help you decide whether the faulty parts should be repaired or replaced:

Test Oxygen Sensor

Inspect the oxygen sensor for breaks, shorts, or exposure. Run the engine for a while to warm it up and insert a key on it. Then use a voltmeter or scanner tool to check signal voltage. You may also need to increase RPM to fast idle to inspect bank 2 voltage. If you find the voltage lower than 0.5V, the oxygen sensor is bad. It can also be a wiring issue.

Test Oxygen Sensor

Test Fuel Pressure

Check fuel pressure using a pressure gauge. If you find fuel pressure less or more than 40 psi, check fuel pressure sensor, regulator or fuel pump.

Test Fuel Pressure

Check Exhaust Pipe

Check exhaust pipes and manifolds for air leaks. In this case, you can use large pliers and squeeze the pipe gently. Any black soot in exhaust pipe indicates a leak.

Check Exhaust Pipe

Update Computer

PCM usually doesn’t require updates based on mileage. Manufacturer released an update to fix some issues. But if a software problem triggers P0157 code, you’ll need to update PCM to fix the issue. In this case, you’ll need to use an advanced diagnosis tool to determine if PCM needs an update.

Can You Drive Chevy Silverado With P0157 Code?

P0157 error code is moderately serious and can cause drivability problems. When driving with a damaged O2 sensor, computer won’t get right reading of air and fuel mixture. Hence the computer won’t be able to ensure a proper air-fuel mixture.

It can cause your Chevy Silverado to stall. It’ll also introduce lean conditions and engine will start burning excess fuel. So your car will produce higher emissions and fail emission test.

If you continue driving with p0157 for a long time, it can damage catalytic converter and engine. So after discovering P0157 code or noticing its symptoms, diagnose your Chevy Silverado immediately. This will reduce the chance of engine damage and help avoid expensive repairs.


What Are The Symptoms Of P0157 Chevy Silverado?

P0157 error will activate check engine light. It can also cause your vehicle to run rough or put it into limp mode. Car engines will increase fuel consumption and produce excessive black smoke.

Where is The P0157 Sensor Located?

The P0157 sensor or downstream O2 sensor is placed near the catalytic converter. If your scanner tool registers this error code, let an expert mechanic inspect and repair the sensor to avoid further damage.

How Much Does it Cost To Fix P0157 On A Chevy Silverado?

Most mechanic shops will cost around $75 to $150 to diagnose P0157 code on a Chevy Silverado. If needed to replace oxygen sensor to clear the error code, they’ll cost around $362 to $412 including labor charges.

Final Words

P0157 trouble code won’t make it risky to drive your Chevy Silverado or stop the car suddenly. But still, you should pay immediate attention to fixing p0157 Chevy Silverado issue to avoid engine stall or rough idle.

You don’t also want to pollute environment with black smoke nor want to pay extra bills for fuel. So after detecting P0157 code, bring the car to the nearest repair shop to check and fix O2 sensor.

My name is Tom Vanderbilt. I am an automotive expert and renowned for my profound knowledge of automobiles. I have made significant contributions to the industry through my experience and expertise. I have a natural curiosity and fascination for cars. My journey is to explore the intricate dynamics between people, their vehicles, and the ever-evolving transportation landscape.

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