The oxygen sensor on the 1999 Oldsmobile Cutlass Sierra is located on the lower exhaust. If you need to replace it, they are available for about $20 online.
The oxygen sensor on a 1999 Oldsmobile Intrigue 3.3 liter is in the exhaust manifold/pipes
most o2 sensors are on the tailpipe between the engine block and the catylitic converter. if you have 2 exahst manifolds, then you should have 2 sensors
DEX-COOL
None
The 1999 Oldsmobile Cutlass OBD 2 port is under driver side dash left of steering column
dextron / mercon type 2
Begin by loosening the tensioner pulley on your 1999 Oldsmobile Cutlass. Put your serpentine belt around the pulleys. Tighten the serpentine belt with the tensioner pulley.
The TCM is the transmission control module and it has nothing to do with oxygen sensors!
You fill the radiator through the overflow tank.
take the complete headlight assembly loose or out to get to the bulb.
That Vehicle has 2 oxygen sensors.
2