Oxy sensor location ?

[soren]

>I'm fitting a (heated) oxy sensor to my car which has an extractor exhaust
>system.  The engine is a Nissan L6 and the extractors are of the 6 into 2
>into 1 type.  There is a flange attachment to the remainder of the exhaust
>system down near the front of the gearbox.     I've noticed that production
>cars with cast iron manifolds have the oxy sensor quite close to the head.
>I would much rather put mine in the exhaust system just after flange, since
>then I don't have to go drilling holes in the extractors - which are
>coated.   Will the sensor still work properly if I do this ??, or should I
>try to put it as close to the head as possible ??
>

    The main reason for the oxygen sensors being close to the head on
production vehicles is to allow the sensor to reach the proper operating
temperature.  Normally I would recommend against relocating the O2 sensor
downstream in the exhaust, but if you are using a heated one, it may not be
a problem (example : many new models using a heated O2 sensor both before
and after the catalytic converter in order to monitor its effectiveness).

Soren