1994 Gs300 Has No Sub Oxygen Sensor?

[mvb59]

Can somebody please tell me where is the Sub Heated Oxygen Sensor located on 1994 GS300? According to the service manual it is located beneath the car on the exhaust pipe, I looked, but there 's no sensor along the exhaust pipe. I lifted up the passenger side floor carpet, removed the ECM protector, but there 're no wires come up thru the floor as the service manual diagram shown. Thanks