Originally Posted by thrice00
Will i need 93 gas if I install a TBE and a coob stage 2 for my 02?
Are the Hi flow cat restrictive. Is the exhaust legal with it?
Yes. Either 91 Octane or 93 Octane gas is required with whichever Stage 2 map you choose. Read the map notes on Cobb's website: CobbTuning.com - Home Page
No. High-flow catalytic converters are not very restrictive at all. They might take away 1-5 horsepower from you (give or take), but it's really nothing major to worry about. The benefits of havng a catalytic converter are that it reduces the smell of noxious odors coming from the exhaust, it makes the exhaust sound level slightly quieter, and it makes it "slightly" more legal - and I use that term loosely.
No. Technically, any modified exhaust is probably illegal in most states. If you want to be sure, check with your local law enforcement agency. Even with a catalytic converter, your exhaust is still probably going to be illegal, although you might
have a better chance of passing a "sniffer" test or visual test when you have your car inspected. Despite the fact that they're probably illegal, many WRX owners have aftermarket exhausts and have not experienced any negative ramifications from law enforcement. If you use common sense and don't mash the gas when you're around the police, you probably won't have any problems, but that's not guaranteed. If you're really worried about that, you could get a single or twin tip, stock-looking exhaust that's 3" and provides the benefits of an angled-exit, canister-type, obnoxious-looking, louder cat back. Many of the non-obnoxious looking cat backs still let you hear the nice boxer rumble too, if you're concerned about that.
One more thing - many WRX and STi owners keep their stock cat back exhausts because if we do get pulled over by the police and are required to "fix" the exhaust, the stock cat back can be swapped back onto the car and then the car can be taken in for an inspection. On the 02-07 models, the stock cat backs are not very restrictive, so they can normally be used with a Stage 2 tune without negative consequences. Switching cat backs is relatively simple also - 2 bolts and several exhaust hangers that just slide out of rubber bushings - several minutes on jack stands and you're done. Just something to think about.