Every time I look on FB or browse the forum I see threads about turbo upgrades and I want to do a evo 9 upgrade in the future. My only hesitation is being able to pass emmissions. Right now I have a TBE and will be getting a tune in a few days to tune the car and turn off that pesky CEL. However I still have my stock ECU and O2 housing which I will switch back in for inspection. The only thing I haven’t been able to find out about doing the turbo upgrade is will it pass a state emissions test? I know most use the BK1 O2 housing so would all I need to do is source a stock BK1 O2 housing with the primary cat and just out that in for the emissions test?