Oxygen sensors?

Welcome to 2CarPros.

That is correct. There are a total of four. You have two upstream and two down stream. Each bank of the engine (there are two banks) has two sensors. I attached a picture showing locations.

Here is a link that shows how one is replaced:

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

Here are the directions specific to your vehicle. The first set of directions and pictures 2 and 3 show how to replace sensor 1 for both the front and rear banks.
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Special Tools Required
O2 sensor socket wrench, Snap-on YA8875 or SWR2, or equivalent, commercially available

Front Bank (Bank 2)

1. Disconnect the front A/F sensor 6P connector (A), then remove the A/F sensor (B).

pic 2

2. Install the parts in the reverse order of removal.

Rear Bank (Bank 1)

1. Disconnect the rear A/F sensor 6P connector (A), then remove the rear A/F sensor (B).

pic 3

2. Install the parts in the reverse order of removal.

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Here are the directions for sensor 2. Each bank has one. These are the heated sensors. Pics 4 and 5 correlate with these directions.

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Secondary HO2S Replacement

Special Tools Required
O2 sensor socket wrench, Snap-on YA8875 or SWR2, or equivalent, commercially available

Front Bank (Bank 2)

1. Disconnect the front secondary H02S 4P connector (A), then remove the front secondary HO2S (B).

pic 4

2. Install the parts in the reverse order of removal.

Rear Bank (Bank 1)

1. Disconnect the rear secondary HO2S4P connector (A), then remove the rear secondary HO2S (B).

pic 5

2. Install the parts in the reverse order of removal.

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Please keep in mind, it isn't normal for all of these to go bad at the same time. If you have a diagnostic trouble code indicating an issue with an O2 sensor, let me know what it is and I can direct you better.

I hope this helps. Let me know if you have other questions or need help.

Take care,
Joe

What you have sounds more like a shorted wiring harness not bad sensors. Also, the front and rear sensors would have different designations. Both would not be B2 S1. Could you post the actual codes you have? That would allow for a better idea of the problem.

If those are the correct codes the description for both are wrong.

P2254: Front A/F Sensor VS Circuit High Voltage B2S1.
P0154: 02 Sensor No Activity Circuit B2S1.

What it means is that the sensor is shorted to supply or bias voltage and is staying there.
I would check the wiring for the sensor and be sure it is not damaged or chewed on. If the wiring looks okay then the easiest test would be to replace that sensor.

The sensor in question will be the first one at the top of the exhaust manifold closest to the radiator when you open the hood.

Hello,

The upstream O2 sensors for both bank 1 and bank 2 are going to be located in the exhaust manifold before the catalytic converter. Both downstream O2 sensors for bank1 and bank 2 are going to be in the exhaust pipe after the catalytic converter. I have included a diagram for you in the diagrams down below.

Thanks,
Alex
2CarPros

Primary Heated Oxygen Sensor (HO2S)In exhaust pipe, forward of catalytic converter.

Secondary Heated Oxygen Sensor (HO2S)On catalytic converter. Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

They could be related. P0135 is a B1 S1 heater circuit malfunction. Could be the heater wires got close to the exhaust or to a spot on the block and melted/rubbed through the insulation. That short could be why the battery will not charge, because a short is pulling all the power.
I would start with a visual inspection of the O2 sensors wiring and see if you locate a bare spot, start at the sensor and work up the harness.

Hi tubergonz,

I don't think there is any relays involved. Check the fuses at underhood fuse box.

The grounding of the circuit is by the ECM.

Hi tubergonz,

The syatem used on your car might have the HO2S getting its power from the main relay.

Check for power at the sensor coupler before looking for the fuses.

If you have a Yellow/Black wire, it should have battery voltage when ignition switch is turned on.

Next to it is the Orange wire and it goes to the ECM.

Measure the resistance of HO2S across the pins, you should get between 10 to 40 ohms. Hope you have wired the sensor correctly.