help code P0137

[yukonaetahoe]

First off, its a 96 gmc sierra 1500 5.7 vortex.
we recently had about 6 or seven codes that came up and all emission related. We fixed them all except this one.
The machine says "oxygen sensor, circuit low voltage,bank 1 sensor 2" now all oxygen sensors we replaced already. The machine also says probable fix is new fuel pump or new oxygen sensor or new MAP sensor.

My question is, has anyone got this code before and did changing the fuel pump work for you? Any info would be helpfull.....
Thank you TYF family!!!

 

[ch4d]

Essentially the same as P0136, P0137 refers to the second oxygen sensor on Bank 1. P0137 means the O2 oxygen sensor's voltage remained low for longer than 2 minutes. This, is interpreted by the ECM as a low voltage condition and sets the MIL. Bank 1 Sensor 2 is located to the rear of the catalytic converter and should produce an output signal relative to oxygen storage capacity of the catalytic converter. This rear (sensor 2) sensor is less active than the signal produced by the front sensor. However, if the ECM senses the sensor is inactive, this code will set.

Symptoms

There may be no visible symptoms to the driver, other than the MIL (Check Engine / Service Engine Soon) illumination.

Causes

A code P0137 may mean that one or more of the following has happened:

Faulty o2 sensor Exhaust leak near the rear sensor
Plugged catalyst
Short to voltage on O2 signal circuit
High resistance or open on O2 signal circuit


Possible Solutions

Replace faulty sensor
Repair exhaust leak near the rear sensor
Check for restriction in catalyst and replace as necessary
Repair short, open, or high resistance on o2 signal circuit