Good fitment & Sound on my 99 Impreza RS
The flex pipe on the headers made it a breeze to install. I use a Mazda rx7 oil filter, which is longer, and it doesn’t interfere with the headers at all. So, a stock filter would fit just fine. The included spacer must be used on the downstream O2 sensor so no check engine light will appear. All hardware and gaskets are included! Although it is a little raspy since there is no cat, but I’m getting used to it.