I am trying to install my highflow cat with my shorty header. I am in need of a second opinion. Long story short I took this cat to a muffler shop and they told me it was the wrong one. I know it has no bungs for the egr or o2 sensors, thats why I am thinking they said it was the wrong one. I need to know if anyone has done this, added this cat with there shorty header. I heard of the egr delete and I am on tom's tune. Before the tune i was throwing p0420 so i ended up buying this cat. Got tuned so really didnt need to install. But now i want to install because I already paid for it, why not right? So I don't really understand why I couldn't get this installed. Should I take it to another shop? I really want to take the svt header route but had no luck in selling this cat so I want to try and install this. Do i need my egr or o2's plugged in? Any feedback would be appreciated. Thanks a million!!