If Catalytic Converter Is Removed, What Should I Do with the O2 Sensor?

[Nehmo]

1996 Chevrolet Lumina APV, 3400 Engine

Currently, the minivan has no pipe between the catalytic converter and the muffler. I intend to fix it by removing the cat completely and installing a new muffler. I can get away without a cat in Missouri, and I might as well install a new muffler. I don't have a welder, but the few connections I need to make can be done with clamps.
What should I do with the O2 sensor? Should I simply remove it? Or should I leave it hanging?
I realize this will produce a diagnostic code and probably the check engine warning. I'm not concerned.

[Blue Bowtie]

1. If the existing converter is not plugged, a new pipe can be fit to that to connect to the muffler. In that case, the rear (secondary) O² sensor can remain in place.

2. If the cat is replaced with straight pipe, a simulator for the rear O² sensor can be installed in place of the original zirconia sensor to "fool" the PCM into thinking it has signal and not set an error code.

This is not an endorsement, just an example of what that is and how it works:
https://www.afterthoughtsauto.com/o2sim.html

You can also construct your own if you like: https://www.youtube.com/watch?v=qHD7T7EhuzI

Of course, the primary sensor will need to be left in place in order to maintain proper mixture control, regardless of what the convert is doing (or if it even exists).

These methods can be used to test whether a rear sensor error is due to a converter problem or wiring fault. The duration of the "test" is completely up to you.

[Nehmo]

Originally Posted by Blue Bowtie

1. If the existing converter is not plugged, a new pipe can be fit to that to connect to the muffler. In that case, the rear (secondary) O² sensor can remain in place.

2. If the cat is replaced with straight pipe, a simulator for the rear O² sensor can be installed in place of the original zirconia sensor to "fool" the PCM into thinking it has signal and not set an error code.

This is not an endorsement, just an example of what that is and how it works:
https://www.afterthoughtsauto.com/o2sim.html

You can also construct your own if you like: https://www.youtube.com/watch?v=qHD7T7EhuzI

Of course, the primary sensor will need to be left in place in order to maintain proper mixture control, regardless of what the convert is doing (or if it even exists).

These methods can be used to test whether a rear sensor error is due to a converter problem or wiring fault. The duration of the "test" is completely up to you.

Thank you for the well-researched answer. At this point, I'll probably simply replace the missing pipe between the cat and the muffler. It's the simplest, however, I suspect the cat is doing nothing considering it's 154,000 miles old, and I should eliminate it. (There's no legal problem here.)

[maxwedge]

Keep in mind, removal of the cat for anything more diagnosing a problem, is a federal violation, regardless of state inspection requirement.

[Blue Bowtie]

Originally Posted by maxwedge

Keep in mind, removal of the cat for anything more diagnosing a problem, is a federal violation, regardless of state inspection requirement.

Correct, thus the "test" qualifier.