Where is the best place to put a wideband O2 sensor? Should it be located as close to the motor as possible? (like a EGT sensor) Of is anywhere in the exaust okay? Which is best: exaust manifold? Down-pipe? Before/after cat?
The closer u can get it to the turbo the better. Mine is 3 inches away. The reason is there will be a lag that is reported vs the rpm u see the a/f in. Up to 300 rpm lag difference when u stick it in your tail pipe.