What difference in wideband reading will you see if you place the sensor post cats vs. pre cats ? Will or should you see a leaner reading post cat @ wot ? If there is a difference does anyone know roughly how many points it varies? Thanks, Ron

 

My tuner told me he sees .2 difference leaner post cats

 

Why even consider placing it after the cats? All the manufacturers state that it should be placed before the cats.

 

.2, Thanks for the reply, My cats bolt directly to L/T Headers, mids have bungs pre installed to accept rear or downstream 02s which are turned off in tune and are well past the 18" that aem calls for sensor placement, not to mention pre cat would require blowing a hole in a critical imo position in the headers ie. merge collector to weld a bung. I would rather buy the Bosch Lsu4 wideband sensor than chop up or hack up my headers, I also believe that midways past the bend on drivers side bank is downstream enough to control heat somewhat in regards to bosch sensor.