Apparently the cat changed from 95-96 to 97+. This changed the arangement of the B-pipe.
Courtesy designed their B-pipe to fit the 97+ so in order to fit on a 95-96 there is a extension piece which needs to be added. This piece has a hole where the rear O2 sensor fits, downstream of the Cat.
The only problem that I have with this piece is, my whole set-up is stainless, this piece is cast iron. Also, I could be wrong but judging by the looks of it, it appears that it would restrict flow horribly. I was hoping to replace with just a straight piece.
My question is, on the 97+ the rear O2 sensor is upstream of the Cat, in the Y-pipe. I have the stillen Y which has a plug where this sensor would go. If I were to reroute my O2 sensor and plug into the Y, would this affect performance, being that it's upstream rather than down?
Has anyone else dealt with this problem, or is it not that big an issue??
Any opinions??
Thanks DBM for all the help on this board, it's definately appreciated!!!!

 

Warning: this answer is in the category of I Think, not I Know.

When the two front Oxygen Sensors are operating properly their signals are used by the Engine Control Module to manage the fuel mixture. Under normal conditions the only function of the rear Oxygen Sensor is to monitor the performance of the Three-Way Catalytic Converter. If you move the rear sensor to upstream of the Cat, the sensor will think the Cat is "dead". You will get that nasty Check Engine Light.

 

Damn...
Thanks again for your help...

 

The solution is simple. Take the extension piece and throw it in your trash can. Go to a muffler shop and have them make a straight 6" X 2.5" extension piece. Problem solved. This is what I did. That supplied extension piece is a joke and I think it's what restricts the flow on the 97+ making them a tad slower (plus the heavier wheels).


Dave

 

How much $$???