galyen

I have a 1995 993, naturally aspirated. I'm replacing the O2 sensors and believe that I have correctly replaced the pre-cat O2 sensor which is very visible at the lower back center of the car (where the exhaust manifolds feed into the catalytic converter). If I am correct that this is the pre-cat O2 sensor, then I'm having difficulty locating the post-cat O2 sensor on the vehicle.

Can anyone help me locate the other O2 sensor. I do not have the service manuals or CDs. Any help is appreciated.

vuugti

There are no "Post-Cats" I just removed/replaced the entire exhaust system, you have replaced the one and only sensor.

Congratulations!


Good Luck,
Andy

galyen

Thanks for your help. The thing that made this particularly confusing is that I have found several parts listings that show pre- and post-cat O2 sensors listed for the 993. When I ordered the parts from NAPA, they said it required two and sold me two.
Thanks again for your help.

Steve Weiner-Rennsport Systems

Galyen:

I'm not surprised that the NAPA books list 4 sensors for 993's.

Their documentation obviously doesn't make the big distinction between the OBD-I and OBD-II 993's.

OBD-I cars ('95) have a single sensor and the OBD-II ('96-'98) have 2 pre-cat and 2 post cat sensors.