Test Pipe and O2 simulator

I've had some trouble with my exhaust set up. The outlet for my headers and the inlet for the catback exhaust are two different diameters so I had a cat custom built to fit, but only a few months and $400 later that cat is shot and I don't want to waste my money on a new one. So I want to go with a test pipe. but two things. Is that going to make my ehaust a lot louder, and also do those O2 simulators acutally work? If so what brand of O2 simulator is good for a 99 Si?

If the cat is bad, you won't pass the emissions test==you know the CO2, hydrocarbons and NOX test regardless of the O2 simulator you might use.

he might not have emmision out in illinios. Some of the midwest states don't even require safety inspections I believe so he might luck out.

Back on topic, yes a test pipe will make the car alot louder.

I have a RS-R exmag on my integra and I built a test pipe for it last summer. By December I put the catalytic converter back on because I was tired of the extra noise. However as you can tell by my choice of exhaust I am no fan of loud exhausts. If thats you're cup of tea you may like having a test pipe on because it will get louder and deeper.

Yeah we have emissions out here in IL but since the car is an OBD2 all they do is plug a computer into the car and as long as the sensors aren't telling the computer that the exhaust is bad you pass. So will an O2 simulator tell the cars comp that everything is working fine.