I bought some DP's and TP's off a guy on Saturday. He didn't know much about Z's and said his buddy purchased them for him "a long time ago". I was hoping they were 2.5" but unfortunately they are 2.25". With that being said I didn't think they were from Z1. However, I've noticed Z1 has (2) diff pics on their site for their DP's. One pic has the o2 bung close to the turbo side while the other pic has the o2 bung further from the turbo side (on the DP). I also notice that IPP has the 2.25" Z1 advertised. Question: Is there any way to identify Z1's from the other Ebay versions? When did Z1 change from 2.25" to 2.5"? I'm assuming they changed the o2 sensor location due to a performance aspect (or my guess is to prolong the life of the o2 sensor). I'm sure these will be an improvement, as I'm all stock in terms of exhaust right now, and my original cats are leaking. Thanks!!!
