Is there supposed to be an Oxyen sensor on the CAT converter, for an 81
federal model?

The CAT I received from busdepot has what appears to be a threaded hole on
the end that connects to the crossover pipe, but in the ETKA software and my
bentley I cannot find a cat diagram that shows this sensor.

On the CA model there is an Oxygen sensor, but its not connected to the CAT.

confused.

I called BD, but they said it should have an O sensor. I clarified that this
was an aircooled federal model, but they insisted that it should be there.
however they are going to mail me the plug for the hole for free.

im just curious if I should just plug it now or try and find this sensor
information.

thanks for any tips...