The exhaust setups on the Y8 vs the Y7 are totally different in general.
The Y8 is a 2 pc manifold which mates to the cat under the firewall area, then to the resonator pipe, the the muffler. The resonator pipe is only from about the driver's seat back to the rear lower control arm.
The Y7 is a 2 pc (I believe) manifold with the cat integrated in the upper piece that connects to the resonator pipe under the engine / firewall area and runs all the way down to the rear lower control arm area.
The mid pipe with the resonator on the Y7 is almost 2 feet longer than the Y8. There is a VERY noticeable difference. Lay the pipe you have on the ground where the rear end of it is next to your rear tire. If the pipe doesn't go past where your door meets your front fender (around that area), then you likely have a Y8 pipe. If it goes up around the front tire, likely a Y7.
