I failed my emissions big time

The reason you passes is because “he overheated” the engine… The motor ran to hot and there for had no choice but to pass (its one tech used to make sure a vehicle will pass)…

Catch is… your motor may not have “overheated” maybe your thermo is stuck open and is never closing and your car isnt exaactly coming up to “running temp” but for some reason did on the dyno during the test ?

Do you got an aftermarket gauge ? If not… may wanna inspect the coolant temp sensor ?