I'm trying to figure out where the best place is to put my O2 sensor. I'm running a Holley Commander 950 PRO ECU that uses one O2 sensor and I bought a Holley Wideband upgrade kit for it that uses a Bosch sensor. The Holley instructions say to put the O2 in the header collector, right after where the tubes merge and gases mix. The problem is that way you only get one bank of cylinders that way.
I understand that if you put a normal O2 sensor too far back in the exhaust it's too cool to control the mixture at idle. But I don't think this is the case for a wideband sensor which is heated. Does it make sense to put the wideband sensor in the x-pipe? The other options are just in front of, or just behind the header collector connection point.