Hey getting ready to install my new Supercharger. Just wondering should i weld the bung for my new AFR gauge right next to my OEM AF sensor. The directions that came with my gauge says the sensor has to be before the CAT.

 

that close im afraid that youll be going through wideband sensors often, the directions will also state how far down the exhaust stream you should place the sensor. If you go by the directions chances are your going to find yourself in a pinch cause of the stock header (as far as placement goes).

you can try out your idea and see how far that will get you or replace the stock header with an aftermarket (catless) unit and place the bung towards the end of the header (flange to s-pipe). or place the bung near the start of the s-pipe.

 

Some folks did some testing, and under WOT, putting the wideband after the cat only threw it off by about .2-.3 afr. (sensor after the cat read leaner) However during cruise and low throttle accell - the wideband after the cat will read considerably leaner. (in alot of cases, maxed out lean) Ill try to find a link - it was on a LS forum (prob LS1tech) and they had two widebands in the car to monitor the difference in realtime.

 

whats so special about the OEM sensor that it could be so close?
really dont want an aftermarket header i think my exhaust sounds perfect the way it is.

 

I had my wideband in the s pipe with the stock header for quite awhile and never had issues with it reading far off during non WOT. As stated you will get a little bit of error.

 

The stock primary o2 sensor is not the same as a wide band, their operating voltages are different and the overall design differs. Follow the instructions that came with the wideband and you should be fine.