Ash;

I noticed that your thread on the differences between the S2 and the S1 show that the S2 has a "revised oxygen sensor after cat". Curious on if you know the part number to the new O2 sensor and what the differences are exactly?

Example, I found a denso plug that lists the entire RX8 linup:
http://www.autopartswarehouse.com/de...NP2344349.html

 

You rang...

Hang on, Yes the PN changed..for S2.

N3R1-18-8G1 Front

N3R1-18-861 CAT (Manual), the S2 Auto's uses the same as S1 Auto.

CATS are different than S1 and twice the price.
I think from memory the Sensor differences are also in the elect plug?

 

Thank you doctor, I appreciate your help :D

 

It's possible that it is just a difference in the wire length. Most aftermarket replacement sensors have plenty of extra wire so they will reach to wherever the application requires.