Adding Autometer oil pressure gauge on 96

Did an engine swap on an XJ awhile back, had inop gauge reading since. Replacing the sending unit and gauge cluster did not fix this so i figured the issue was in the harness somewhere.

It came back in for more work and he brought me an electrical pressure gauge to install as well. In the instructions it mentions t'ing off to keep warning light operational.

Anyone familiar with this? Can i just eliminate the OEM sending unit and leave the harness plug disconnected? Will this give the vehicle a CEL?

I have left the wire off the sender (guage style) several tmes after an oil change....never had a CEL light only no pressure reading......If the cluster has only warning light then I would hope it would be on.....

Wayne, OBDII?

EDIT: Just checked your profile and see you also have a 96. That answers my concern...thanks Wayne.