I replaced my catalytic converters and the O2 sensors on my truck about 3 months ago. I was running with no cats, and that is what I thought was causing the problem, but driving to school this morning I got a code (P0161). Can anyone help me out, which sensor is it talking about? Any short cuts for getting around this problem in the future? Thanks. Let me know.

 

That is a driver side rear o2 sensor. I would just disable it.