On my 1998, I switched to the 2000 down pipe and 2 piece exhaust manifold years ago. I had an issue last year and wanted to purchase a new 2000 down pipe without the cats but was unable to due to the fact no one is making them any longer. I went back to a 1998/1999 style header with the bellows pipes for the 1998 year. You O2 sensor may be ok. Where is the connection on the wiring harness? Passenger side?
The connection is on the passenger side. it goes across the back of the motor bundled with some other connections and goes under the passenger side.