There is more than one O2 sensor on that Mercury Cougar and they are all threaded into the exhaust system at various points.
Where is the O2 sensor on 1997 Chevy Monte Carlo 3.1 litter with 8th digit vin M
It is the O2 sensor screwed into the front of the catalytic converter
YesYes
exhaust pipe
4
4
There is a total of 3 O2 sensors 2 Upstream and 1 Downstram
The upstream O2 sensor is mounted in the ehxaust manifold The downstream O2 sensor is mounted in the exhaust pipe after the catalytic converter
2
That would be the O2 sensor after the catalytic converter.
The '97 is OBDII. There are 4 different O2 sensors on the '97 Cadillac. http://www.airbagcrash.com
All O2 sensors are threaded into the exhaust system at varoius points.