Q: SENSOR 1 BANK 1 O2 SENSOR LOCATION on 2003 Land Rover Discovery

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I just had an O2 sensor replaced. I am not sure if this was bank 1 or bank2. I am going to attempt to do this one myself. What is the location of the o2 sensor that is regarded as bank 1, sensor 1. I am noticing a rough idle. Not sure that this code is accurate but hoping this will remedy the issue. i have two other trouble codes that it throws when using the reader but believe these to be a result of the initial o2 sensor code. P1171 p0171 and p0134. I cleared the codes three times to make sure it was consistent. It seems to be throwing the same three codes each time the Service Engine light comes on.
(1) Answer
(1) Comments
its the other way around. the 171 is an indicator of a veccuum leak which may trigger the o2 sensor reading. the o2 cannot compensate for the change of long term trim and is now asking for help. dont throw parts at it. get a real diag and then you can get an idea of what needs to be replaced.

Thank you very much mastertech6371 for the prompt response. How would I test the vacuum leak or how would a shop? Where would an 02 sensor (bank 1, sensor 1) be located?

Is there any way to determine which may be the culprit above the other?

Obviously I am trying to avoid a shop that is why I have posted on the forum to try to remedy this myself to save some costs.