02 sensor bank 1 sensor 1-Is this drivers side or Passenger

[cballweg]

I have a check engine light code P0135 on my 1999 LS1 Trans Am that I looked up and it says 02 sensor bank 1 sensor 1 and Im wondering if this is drivers or passenger side and is this the one closest to the motor and where is this located.Any help would be much appreciated.Thanks for your help.

[35th-ANV-SS]

You are correct. Bank 1 is the driver's side and sensor 1 is the O2 sensor upstream of the catalytic converter.

[Mr_Rich]

I think it's the upstream driver's side sensor. They're fairly simple to remove. You can always swap the upstream with the downstream sensor to isolate the problem. All four sensors are swap-able. In the books the sensors have been superseded by the same part no.

[cballweg]

Thanks for your help.I have long tube headrers so I believe Ill have to get it from under the car since they are at the back of the headers

[35th-ANV-SS]

You can access from underneath. I believe the wrench size is 7/8"