Over time the 02 sensor in your Chevrolet can come to be fouled or fail every together. If you very own a late design vehicle, over there are numerous oxygen sensors in your car. Depending on the place of these 02 sensors, they will do different things. Because that instance, the upstream or prior oxygen sensor is primarily responsible for your fuel injection. When your prior Impala oxygen sensor go bad, it’s going to cause your Chevy to run poorly.

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As your Chevy is running, contaminants in her fuel can lead to the ultimate fouling that the Impala oxygen sensor. When this happens to the 02 sensor, otherwise well-known as the Impala oxygen sensor, it should be replaced. This particular day I’ll be mirroring you just how to check the primary Impala oxygen sensor in a 2001 Chevy through a 3.4 liter engine in it.


When the Impala oxygen sensor fails in her Chevy, there’s going to be number of symptoms the you’ll see. Few of these Impala concerns are provided below that stem indigenous a failure oxygen sensor.

Common Impala concerns from a failed oxygen sensor

When the primary or upstream Impala Oxygen Sensor walk bad, here’s simply a few of the symptom you’ll see.

Bad gas mileageSluggish performanceImpala won’t startCheck Engine light ON

One that the an initial Chevy Impala concerns you will check out is that course her OBDII check engine light. This is otherwise recognized as the OBDII breakdown Indicator lamp or MIL. Once you watch your Chevy Impala company light on, you’ll need to use a OBDII scan tool to read the stored alphanumeric code.

The auto we room working on today has actually a save on computer OBDII check engine light because that the P0131 inspect engine light. The exactly language because that this particular code is O2 Sensor Circuit low Voltage bank 1 Sensor 1. This trouble code means that your Chevy engine computer system is receiving a short voltage signal from her upstream oxygen sensor.

Possible causes to P0131 Impala problem code

Because the upstream Impala oxygen sensor is sending out a low voltage, it’s usually brought about by fuel delivery problems. Several of these worries can reason your Impala to litter a P0131 problem code.

Bad fuel pumpPoor fuel or contaminated fuelClogged or leaking fuel injectorsBad MAP sensor or MAFFailing Impala Oxygen Sensor

Impala Oxygen Sensor terminology

Before we being testing your upstream Impala Oxygen Sensor, there’s a couple of terms you should nail down. Understanding these terms will assist you recognize what sensor is what on her engine.

O2S11 – This sensor describes the upstream sensor ~ above the financial institution 1 next of your Impala engine.Downstream – This describes the sensor that’s mounted after her catalytic converter.Sensor 1 or Sensor 2 – these terms refer to the main or Sensor 1, and also the downstream or Sensor 2.Catalytic Converter – This is the emissions equipment that’s mounted to your exhaust piping straight after your exhaust headers or the collector to your headers.

Testing your Impala Oxygen Sensor

In bespeak to begin our overview to testing your Impala Oxygen Sensor, you’ll require a digital multimeter. This machine will assist you identify where the fault is in her Impala oxygen sensor. Once you are prepared to start testing your Impala O2 sensor, you’ll need to find your trouble sensor and also unplug it.


Before you start testing the wiring harness directly, you’ll be using the OBDII scan device to check out what your engine computer is seeing. Due to the fact that the P0131 OBDII trouble code describes your Impala oxygen sensor sending out a low signal, you’ll inspect to view what her Impala computer system sees real time.

Often time the P0131 check engine light will be accompanied with other codes. If the P0131 trouble password is the just one in your Impala On plank Diagnostic Computer, then every you’ll require is a scan device to proceed.

In order to check the P0131 Impala trouble code, plug in your OBDII scan tool and scroll come Live Data. The P0131 OBDII trouble code method that her Impala computer system sees a voltage from her upstream oxygen sensor that’s listed below .5 volts. In order to inspect this, you will be analysis the Live Data, or the info that your computer sees genuine time.

Turn the crucial to the “ON” position, and you’ll be utilizing the linked OBDII scan device to read the Live Data information. Scroll to the ar where it displays front oxygen sensor information. The field you are looking for is labeled with O2S11. Now that you’ve got the ignition turned to the top top position, and also the scan tool connected, you are ready to go.

Start her engineAllow the engine to warm up

When her cooling fans turn on, the engine is warmed up and also ready because that testing. The PID you will be reading is the O2S11 field. This is the ar that reads the voltage from the upstream Impala Oxygen Sensor.

Look at the PID for the prior oxygen sensor. A usually operating oxygen sensor will certainly oscillate between 0.100 Volts and 0.900 volts of signal. If girlfriend don’t watch this value in the PID field, simply make certain you don’t have a worth under .5 volts. If the sensor reports a low voltage, or it’s stuck below .5 volts, it’s time for a instead of sensor.

If you do get a reading but it’s no under .5 volts, something rather is leading to your P0131 problem code. To test the upstream oxygen sensor, you’ll be disconnecting a vacuum hose the runs to your intake manifold.

Now gradually spray part carb cleaner right into the entry manifold. Girlfriend can likewise use her left PCV valve hose together well. If your Impala engine stalls out, you’ve sprayed as well much. After ~ injecting her engine through some carbohydrate cleaner, check your OBDII scan device again.

Your Impala computer should currently report a reading above 0.800 in the O2S11 PID field. When you space done spraying the engine should slowly burn off the overfill fuel in the burning chamber. When this wake up the PID sensor worth will fall earlier down to a common range.

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If this does no happen, your front Impala oxygen sensor need to be replaced. Unscrew the old O2 sensor and also install your replacement. You’ll have to use her OBDII scan tool to clear her Impala trouble code.