If I run a Test Pipe, and add the spacer to the rear Oxy Sensor, will my CEL remain off? And, if my CEL remains off, why will I fail emissions? I'm in New Jersey and all they do is plug into my OBD port, and I've never seen them open the hood on a car (to visually look for the Cat). Anyone else lucky enough to live in NJ (or other locations with similar testing) care to comment?

 

Do they perform the sniffer test (where they probe for exhaust emissions)?

 

Nope, not since 2010. NJ brothers, am I correct?

 

no, you will pass emissions if the cel is off. you can have pending/stored codes and still pass. as long as the cel is off and your readiness state is good you will pass.