www.RnRracing.com I see that they do have a T3/T4 downpipe listed on their site, but it doesn't mention anything about being O2 Elim. I'd go to the site, and just contact them. Because he can more then likely make just about anything, all you have to do is write and ask.
BTW, RnR stands for Ryan n (insert fathers name here that starts with an "R"). It was just him and his dad for the longest time running the whole shop. Used to be a great guy. I knew him right before he actually opened up a shop. He used to just build this stuff on the side for the local socal community. But then he opened up a shop, got larger, and had a whole 2 people working there so they got real behind, and have never seem to catch up. Good luck with them, you really have to be patient with him.