What is the P0137 Code?

The P0137 code shows that there’s a problem with one of the oxygen sensors in your vehicle. It’s a generic OBDII code that can be read with a diagnostic scanner.

We will be evaluating the meaning of P0137. The causes of the P0137 code are also discussed. We will show you how to remedy the issue. 

Definition of the code P0137

P0137 – Oxygen O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)

What is the P0137 Code?

The generic powertrain trouble code indicates there’s a fault with the second oxygen sensor located on Bank 1. The oxygen sensor’s voltage was too low for at least two minutes, which is why the code was set. The ECM reads and sets the voltage.

Bank 1 Sensor 2 can be found at the rear of the catalytic convertor. It’s meant to output a signal that shows the oxygen capacity of the catalytic converter. It’s not as active as the front sensor but must still maintain an appropriate amount of voltage to work correctly. 

RELATED: Bank 1 vs Bank 2 – Sensor 1 & 2 (Locate O2 Sensors Fast & Easy)

P0137 Trouble code Symptoms

An illuminated Check Engine Light is the main issue with P0137. In most cases, this is the only indication that there’s something wrong.

There shouldn’t be any other symptoms of an issue. However, you don’t want to ignore the problem merely because it’s not causing trouble. 

The P0137 Code: Causes

The oxygen sensor located behind the catalytic convert is responsible for most of the P0137 codes. 

Below are some possible causes for the P0137 Code:

• Defective oxygen sensor
• Sensor detects exhaust leak
• Blockage of catalyst
• Circuit for short circuits between O2 and electrical power
• High or open resistance for the oxygen sensor circuit
• Condition of a lean engine

Is the P0137 Code Really Serious?

Medium – You probably won’t notice any symptoms of the P0137, leading you to believe it’s okay to continue driving the car. This false feeling of security is misleading. 

Depending on what’s causing the P0137 code, you could allow engine damage to occur. You should immediately have the engine repaired if it is lean due to the fault. 

Which Repairs can Fix the P0137 Cod?

These are repairs that could fix the P0137 error code. However, it’s important that you perform a proper diagnosis before replacing any parts, or you could be wasting your money.

• Replacing the defective O2 sensor
• Fix exhaust leak
• Repair restriction by replacing catalytic converter
• Fix an O2 signal circuit short

Common errors in P0137 diagnosis

Inspecting the sensor too often is the biggest mistake in diagnosing the P0137 error code. In some cases, it’s simply a matter of cleaning off any contamination that has gotten on the O2 sensor. 

It is important to first examine the problem before replacing costly parts. Run through the proper diagnostic steps to ensure there’s no wasted money. 

Recommendations for Diagnosis

How do you diagnose the P0137 trouble code?

This is an overview of how to diagnose P0137 codes.

1. Check the O2 sensor to see if there are any signs of contamination. 
2. Verify the O2 sensor wires are free from corrosion and faulty connections. 
3. Look for any exhaust leaks prior to replacing the sensor. It is important to inspect the intake and vacuum connections. It’s possible something has become disconnected. A vacuum leak may be indicated by a hissing sound. Spray some water onto the intake to check for leaks. Pay attention also to idle RPM. An intake leak is indicated if the idle RPM falls. To check for leaks, you can spray water onto the gaskets or hoses. 
4. You can monitor the voltage of your sensor with a warm engine. The voltage should be between 0.01 and 0.95 Volts. It is possible that the O2 sensor has a problem if it is lower than this. 

The estimated cost of repair

Some of the repairs won’t cost you anything, especially if you just need to clean off the O2 sensor. These are just a few other fixes and approximate prices. 

• Oxygen sensor – $150-$350
• Exhaust repair – $100-$300 (more if welding is required)
• Repair Vacuum leak – $100-$250
• Catalytic converter – $800-$2500

The P0137 Code: Mechanics Tips

If there are other codes set with the P0137 DTC, it’s important that you address those first. You might not be able fix the P0137 code if you address another issue. O2 sensors have an internal heater that ensures they stay above 600 F. The O2 sensor can throw this code if the resistance to the heater gets too high. That’s why you would want to deal with the O2 sensor heater DTCs first.

You can only be certain that the oxygen sensor problem is being addressed by first looking at other codes.