How To Test The Oxygen Sensor (Nissan 2.4L -Altima, Frontier, Xterra)

This tutorial will help you to test the upstream oxygen sensor on your two.4L Nissan Altima, Xterra or Borderland and/or troubleshoot OBD II codes P0131, P0133.

The upstream oxygen sensor is the one before the catalytic converter and is also known equally O2S11.

Important Suggestions And Tips

TIP 1: You volition demand a browse tool to utilise the testing info in this article. Your scan tool must have Live Data capability since a unproblematic code reader won't help you.

You don't demand the Nissan factory scan tool or an expensive professional technician level browse tool to follow the test procedures in this commodity, since a uncomplicated generic browse tool will do simply fine (Don't accept a scan tool? Need a scan tool? Bank check out my recommendation: Actron CP9580 Scan Tool Review).

TIP 2: The oxygen sensor test, I'one thousand gonna' testify you in this article, is an on-car test, and then you do not need to remove it to test information technology.

Symptoms Of A Bad Oxygen Sensor

The effects of a bad oxygen sensor can be very subtle since they usually do not cause serious bulldoze-ability problems. Here are the near common symptoms:

  1. The cheque engine light (CEL) volition be illuminated on your instrument cluster.
  2. The diagnostic problem codes lighting upward the CEL usually are:
    • P0131 Upstream Heated Oxygen Sensor (O2S11) Circuit Out Of Range Low Voltage (Bank one).
    • P0133 Upstream Heated Oxygen Sensor (O2S11) Circuit Wearisome Response (Depository financial institution 1).
  3. Really bad gas mileage.
  4. Won't pass state mandated emission testing.

Oxygen Sensor Basics

The job of the O2 sensor in your 2.4L Nissan Altima (Borderland, Xterra) is to assist the PCM (Powertrain Control Module = Fuel Injection Computer) fine-tune the corporeality of fuel that it injects into the engine.

If the PCM injects also much fuel, the air/fuel mixture turns Rich. If it doesn't inject enough, the resulting air/fuel mixture is said to exist Lean.

The O2 sensor measures how Rich or Lean the exhaust is and reports information technology back to the PCM.

Here are some more than specifics:

  1. If the PCM injects too much fuel into the cylinders, the air/fuel mixture will turn Rich.
  2. The oxygen sensor reacts by producing a voltage above 0.500 Volts. This voltage value can get equally high every bit 0.900 - one Volts DC.
  3. When the PCM sees the oxygen sensor voltage above 0.500 Volts, it injects less fuel.
  4. As the PCM begins to inject less fuel, information technology may go too far and not inject enough. This causes the air/fuel mixture to plow Lean.
  5. The oxygen sensor reacts by producing a voltage beneath 0.500 Volts. This voltage value tin can go as low as 0.100 Volts DC.
  6. When the PCM sees the oxygen sensor voltage below 0.500 Volts, it injects more than fuel.
  7. This process (of adjusting the amount of fuel injected) past the PCM goes on the unabridged time the engine is running.
  8. A correctly working O2 sensor will produce a voltage that will switch between a Lean and Rich condition several times every few seconds. So, if the voltage output of the O2 sensor stays stock-still (when testing it), the O2 sensor has failed.

The cool matter is that you lot tin see these oxygen sensor voltage changes with a scan tool in Live Information mode, and this is how I'm gonna show y'all how to test them.

Examination 1: Inducing A Rich Condition

How To Test The Oxygen Sensor (Nissan 2.4L -Altima, Frontier, Xterra)

To test the oxygen sensor (O2S11), the very first matter y'all'll practice is to induce a Rich condition.

This tin easily be done by spraying a little carburetor cleaner into the engine while it's running. My preferred method is to spray carb spray into a vacuum hose.

Once the carb spray hits the engine cylinders, you'll become an instant Rich condition which will brand the O2 sensor answer by producing its maximum voltage (0.900 Volts +) and you'll exist able to see this on your scan tool (in Live Information mode).

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Alright, this is what you'll need to practice:

  1. 1

    Offset your vehicle and let information technology idle for near 15 minutes. This will let the engine to warm up and activate the O2 sensor.

  2. 2

    Connect your scan tool and get to its Alive Data mode.

  3. 3

    Scroll downwards to the PID that's labeled O2S11. This PID will show y'all the oxygen sensor voltage activeness.

  4. iv

    You should see the O2 sensor voltage numbers moving between 0.100 and 0.900 Volts constantly.

    If the voltage value stays fixed, don't worry most this nonetheless, continue to the next stride.

  5. 5

    With the engine running, spray a little carburetor cleaner into a vacuum hose (that has engine vacuum) while you lot discover your scan tool's display screen.

    Yous're non going to exist able to spray carb cleaner into the throttle as the engine is running, considering if you were to do this, the engine will die equally soon as you lot disconnect the air duct from it (to spray into it).

    If you lot spray too much, the engine will stall. If this happens to you, merely restart the engine and echo the step and spray less carb cleaner spray.

  6. half dozen

    Y'all should encounter the O2S11 voltage values immediately spike to 0.800 to 0.900 Volts. And equally long as yous're spraying, these voltage numbers should stay there.

  7. vii

    Stop spraying carb cleaner into the vacuum hose and let the engine idle for most 1 minute.

  8. 8

    The O2 sensor values should come downwardly. Inside a few seconds, they should start oscillating between 0.100 Volts to 0.900 Volts.

Let'south take a look at what your test results mean:

CASE 1: O2S11 voltage numbers spiked to 0.900 Volts when you lot sprayed carb spray into the vacuum hose. This is the correct and expected test effect and lets yous know that the O2 sensor is reacting to the Rich status y'all induced.

The next examination is to make sure that the O2 sensor reacts to a Lean air/fuel mixture. Get to: Test ii: Inducing A Lean Status.

CASE 2: O2S11 voltage numbers DID NOT spike to 0.900 Volts when you sprayed carb spray into the vacuum hose. This confirms that Banking company 1 Oxygen Sensor 1 is no longer working. You can replace the oxygen sensor.