I went to a smog test station in SoCal that surprisingly wasn't even doing the sniff test. They said for newer OBD-II cars they were just checking codes + visual + something else. It was a beta run or something and not at every station.

A test pipe, is definitely not visual legal though, will instantly fail for that

 

Which smog station was this at?

A testpipe with OEM heat shields may pass visual.

 

^wont pass sniff test in CA without cat. They dont even have to look it will test bad.

 

Santa Monica Smog Check on Pico Blvd. I was testing my old Prelude, didn't see any sniffer results, then the guy explained why. The printout had the usual CEL PASS and various other electronic systems

 

Maybe you could get away with it here in MD. Third time since I've owned the car, I went in last week -- third time they completely faild to find the OBD port and, after ten minutes, "passed" the car and sent me on my way.