i've been looking at getting a downpipe without a cat because where i live they don't check emissions and i'm pretty sure i could pass it if they did without one but i'm stupid when it comes to all these sensors and everything so where exactly is the 02 sensor and aren't there two of them? also i've read on VFAQ if you dont' have a cat you'll get a CEL light and can fix it by doing something to the 02 sensor so is that fairly easy. i'm wanting to do the downpipe install and everything myself and was needing to know where all this stuff was at and how to avoid screwing something up. and one more thing if i get a 3" downpipe will it fit good on both ends without to much trouble? TIA

1997 Mitsubishi Eclipse GSX: K&N Filter, John Sheppard built transmission with GVR4 1st gear, autometer boost gauge, "free mods", Greddy type-s BOV, broken shifter