Like Keeth said, tip shouldn't make a difference. From the cat back, they don't really seem to care. One muffler, two or even no mufflers, glasspacks or fart cans, it really doesn't seem to matter when smogging. Cops may at some point, if your pumping out some serious decibel levels, but its amazing how loud some of the vehicles are, without being pulled over.
Not too sure about all the nuances of what happens if you can't pass smog. Somebody else might chime in and give some good info. From what I understand though, if you've done everything possible to get your car to where it should pass and it still doesn't, I believe there is some kind of waiver that may allow you to still drive. If you don't pass, you have up to at least the time of when your plate tags expire, before you have real problems with being pulled over etc.
Cool, nice review for Benny!
'87 Series 3