I am going to get a downpipe for my '05 STi. Are you guys all going catless? I DO NOT wish for much more volume from the exhaust. How will the catless or catted downpipe sound with the remaining exhaust system stock?
if you are only removing the cat from the DP, and leaving the rest of the system stock, you will only notice a deeper rumble when idling. the exhaust note will not change that much. one thing you do have to worry about when changing your DP on an STi, is that you will be susceptible to boost creep. not all people have experienced boost creep, but every car is different. i have done some research on this, and it seems like the people that had the boost creep problem got the wastegate on their turbo ported. i would recommend that before you do the DP, you get some EM (Cobb has a pretty self explanitory and safe system to use), and then get the DP. if you don't have a boost gauge, get one right away. the boost gauge will allow you to see the boost creep if you get it. i would do some more research before you do any of this, so that you know what you are getting into. hope this helps. darrick
