I need to find out which oxygen sensor location is bank 2 sensor 2. Is that upstream or downstream after the catalytic converter?

You have 2 of those and also 2 downstream. You have two banks of cylinders and each one has an upstream o2 sensor and it is located in the exhaust manifold for each bank. Your scan tool should say Bank 1 or Bank 2.

The downstream sensors are after the catalytic converter.

What are the symptoms of a bad upstream O2 sensor? Sensor 1 Sensor 1 is the upstream oxygen sensor. It is the sensor that measures the oxygen content in the exhaust, providing an input to the computer, which determines how to adjust the air/fuel ratio. Sensor 1 is the sensor closest to the engine. Sensor 2 is the downstream oxygen sensor.
Mar 10, 2021

Bank 1, Sensor 1? Upstream or Downstream? - Newparts.com

https://www.google.com/search?q=2015+Chevy+Impala+3.6+upstream+o2+sensor+location

catalytic converter .
In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide.
The powertrain control module (PCM) has the capability to monitor this process by using a rear-heated oxygen sensor (HO2S 2). The HO2S 2 , located in the exhaust stream past the catalytic converter, produces an output signal which indicates the storage capacity of the catalyst. This in turn indicates the catalysts ability to convert the exhaust emissions effectively. If the catalyst is functioning properly, the HO2S 2 signal will be far less active than the signal produced by the front oxygen sensor (O2S 1).

In the OBD codes, sensor 1 failures are upstream and sensor 2 failures are downstream. If you have more than 2, then Bank 1 is for the ODD cylinders and Bank 2 is for the EVEN cylinders.

One would need the year, make, model, and engine size to tell you exactly where they are and how many.

O2 sensors are always in the exhaust stream, either in the exhaust manifold that is attached to the engine, or in the exhaust piping after the exhaust manifold. Some models have one for each bank of the engine, and some have only one sensor to monitor oxygen content. These engine sensors that the computer uses to "fix" or adjust the air/fuel ratio are called the upstream oxygen sensors. If the car is equipped (as most are today) with an oxygen sensor after the catalytic converter, this is called a downstream oxygen sensor. They are the same and do the same thing, but the downstream sensor is only used to monitor the efficiency of the converter. The upstream sensor(s) are what the computer reads to adjust or "trim" the fuel delivery.

So some older cars have only one o2 sensor. Not far from the engine in the exhaust stream. Some newer cars with dual exhaust (2 converters) may have four o2 sensors. 1 for each bank of the engine and 1 behind each catalytic converter. A 2005 Buick Century with a 3.1L engine, for instance, has only two o2 sensors: one (upstream) in the exhaust down pipe, and one (downstream) just behind the catalytic converter.

Here is the low-down on oxygen sensors, and their location designations explained:

Oxygen sensors are screwed into the exhaust system at various points. Some people say that there are 4 oxygen sensors, but technically, that is not correct. Only the front 2 are considered oxygen sensors.

These oxygen sensors are screwed into the exhaust pipe or directly into the exhaust manifold, one on each bank. Because they are in front of the catalytic converter, this is often referred to as 'upstream'.

The other 2 are actually called catalyst monitors. They are oxygen sensors, but they serve a different purpose. They monitor the activities of the catalytic converters, thus the name, catalyst monitors. They are screwed into the exhaust one on each bank, after, or downstream, of the catalytic converters.

On a 4 cyl engine, there are only a total of two such sensors, the one in front of the catalytic converter is the O2 sensor, the one behind the cat is the catalyst monitor.

The location names for them are as follows:

• On a 4 cyl, the front / upstream is called "bank 1 sensor 1" and the rear / downstream sensor is called "bank 1, sensor 2."
  
  
• On a V6 or V8 engine:
  
  
  • the passenger side bank on a forward facing engine, or the bank closest to the firewall on a transverse mounted engine, is bank number 1, so the forward / upstream sensor on that bank would be "bank 1, sensor 1."
    
    
  • The driver's side bank (forward facing mount engine), or front bank (transverse engine) would be bank number 2, thus the forward / upstream sensor on that bank would be "bank 2, sensor 1," and the rearmost / downstream sensor on that bank would be "bank 2, sensor 2."

The answer depends on the type of exhaust system you have. You will have either 3 or 4 total O2 sensors on your V8. If you have single exhaust with a single catalytic converter then you will have 3 O2 sensors (2 upstream sensors & one downstream sensor - "up or down stream" meaning before of after the catalytic converter). If you have either dual exhaust and/or two catalytic converters then you have 4 O2 sensors (2 upstream & 2 downstream). If you have an MIL light (malfunction indicator light, or "check engine light") the code will indicate "front bank / bank one", which is one of the 2 upstream O2's before the catalytic converter(s), or "rear bank / bank two", which is one of the O2's after the catalytic converter(s).

On all cars, the bank 1 is where the first piston is...Your firing order on that car which is the first piston...Buy a chilton or a repair manual for your car and it will tell you which firing order your motor has....Its usually on the right hand side...Passenger side...Rule of thumb if you look at the spark plugs the one closest too you is usually the first piston....Bank 1 is located on the same side as the first piston...I hope this helps...

Fig. Fig. 3: Oxygen sensor-4.3L engines

Fig. Fig. 4: Oxygen sensor-5.0L and 5.7L engines

Fig. Fig. 5: Oxygen sensor-7.4L engines

Oxygen sensors are always numbered like this:
Bank 1 sensor 1
Bank 2 sensor 1
Bank 1 sensor 2
Bank 2 sensor 2

Some manufacturers use a kind of shorthand that reads different, but means the same thing:
Sensor 1/1 or O2s 1/1
Sensor 2/1 or O2s 2/1
Sensor 1/2 or O2s 1/2
Sensor 2/2 or O2s 2/2

Bank 1 is always the side of the engine where cylinder number 1 is located and, of coarse, Bank 2 is the opposite side.
On a 4 cylinder engine, there is only 1 bank and it is always referred to as Bank 1.

Sensor 1 is always the upstream sensor (the one located BEFORE the catalytic converter)
Sensor 2 is always the downstream sensor (the one that is located AFTER the catalytic converter.

Hope helps (remember to rate this).

Fig. Heated Oxygen (HO2S) location (sensor 1)-2.4L engine



Fig. Heated Oxygen (HO2S) location (sensor 2)-2.4L engine



Fig. Heated Oxygen (HO2S) location (bank 1, sensor 2) (bank 2, sensor 2)-2.7L engine



Fig. Heated Oxygen (HO2S) location (bank 2, sensor 1)-2.7L engine

I hope help you with this (rated this help). Good luck.

1/1 is upstream sensor on the number 1 cylinder side, 1/2 is the downstream of the number 1 cylinder side, 2/1 is the upstream of the number 2 cylinder side, 2/2 is the downstream of the number 2 cylinder side. Hope this helps.