Q: Can you pass emissions with a turbocharged car with odb-2 if it did not originally come with a turbocharger?

Can you pass emissions with a newly turbocharged car that has ODB-2 that does not come with a turbocharger from the factory?

It is illegal to modify any factory installed emissions system on a motor vehicle. Adding a turbocharger is not necessarily a modification of the existing emission controls, particularly if the turbocharger is CARB (California Air Resources Board) certified. As a practical matter, in emissions testing jurisdictions where the test protocol is simply to connect to the onboard OBD-II system, so long as all I/M monitors display a "ready" status, and the check engine light is not commanded on (the station will look for MIL status, NOT whether the light is actually on or not) then your vehicle will pass emissions. If the jurisdiction performs additional testing apart from what I just described, the answer is it depends.

Can you opt for the sniffer instead?

If your jurisdiction uses the onboard OBD-II system for emissions testing, if it fails that "test", use of the sniffer is not going to help you. If the jurisdiction uses exhaust testing, you are basically stuck with whatever result is achieved as your car operates at present.

Can you use a piggyback or standalone legally?

Any turbocharger system that is CARB certified is legal to use so long as you are within the scope of the certification published by CARB. See, for instance, this example CARB certification.

If you were to pass emissions would/could a cop right you a ticket?

if you have installed a CARB certified turbocharger, certified for your application, all you would need to do is produce a copy of the certification if you were ticketed for any equipment violation.

If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.