V12 aston.

For the mechanics, regarding O2 sensors for this car,is it true the pre and post catalytic O2 sensors are the same part? How can this work?

 

The front O2 sensor senses the burned mixture coming out of the cylinder.

The rear O2 sensor senses the catalyzed mixture coming out of the cat.

Hint, at temperature (~2000dF) the reduction chemistry on the exotic metals only takes a few hundred nanoseconds.

 

Perhaps the front and rear sensors are the same part number, but OBD2 cars must have separate pre and post converter sensors.

 

I think the first sensor prior to the cat inputs to the computer for fuel mixture. The second compares to the first to see if the cats are "catalyzing".

Bill