When I bought my '99 it had an Innovate Wideband that had its own o2 sensor on the downpipe and did not use the stock sensor or plug. After taking the wideband and sensor out I put the stock sensor back in but I am unsure as to which harness the stock o2 sensor plugs into. Can anyone tell me or possibly post a picture of where this harness is? Thanks!

 

If I recall correctly, one of the sensor harnesses is at the rear, drivers side of the engine. It follows the block down to the transmission and connects to the top o2 sensor. The rearward o2 sensor is near the transmission tunnel by the drivers side seat below the center console underneath the carpet, you might be able to get to it via the ebrake, but you will most likely need to remove the seat.