I recently installed Buschur Turboback Exhaust with Hi Flow cat
and about few days later SES light came on, it was po420(inefficient catalytic convert below threshold). I contacted David about this and he asked if I screw the o2 sensor into the small metal piece first ,then into the bung of the exhaust.
I dont recall putting small metal piece to the 02 sensor...I just remember screwing the o2 sensor into the bung of the exhaust.
What is this small piece of metal??? any idea what it is??

 

anyone??

 

is it like a gasket, is kinda hard w/o a pic, but just a guess

 

I dont know David just said its a small silver metal that screws into the o2 sensor
then i have to screw into the bung of the exhaust, but I never found any metal piece that came with the installation kits..