Mazda Talk Forums

First O2 sensor in the system is a wideband. Assuming it is working properly the car tunes the fuel to the setup according to the maps installed by the factory. Thus, if you install a header that would otherwise make it run a bit lean, it should re-tune to the new setup. Every NC that I have owned has quickly learned the changes of the numerous headers I have tested.

I will note that now and then we see a customer car that does not automatically learn the new setup as it should. Sometimes it is an issue with that factory O2 sensor, and sometimes I don't know the reason (which is where the tuners can really help even more).

Just got my new wheels fitted and aligned.
Enkei pf01 17/8 with 235/40/17 Yokohama S-Drive tires.
Based on Pat's advise and factoring in that I currently don't track, the setup specs are as follows;
Camber -1.5 degrees all around.
Caster +6.3 degrees
Front toe in 0.1 degrees
Rear tow in 0.2 degrees.
So far I'm happy with it.