I put mine on the drivers side between the two cats,, then checked it with the dyno reading,, both read the same so i guess it is ok where i put it, also amjerry did my tune and set the af at 11.7 to 12.1 and my readingin the car is 11.7 at wot. with SC pully, 16lbs of boost so i could run a few more lbs of boost without adding fuel. jim