So we are looking at a total of 3 Cats? 1 on the DP, 2 on the exhaust... Ryan, if anything you may want to do a Cat Delete, or get some HFC's to replace the 2nd cats, if your worried about emissions. I know when I get my N55 X5, i most likely will replace the 2nd Cats with HFC's, probably 2-300 cell count... My question is what is the cell count on the 2nd cats? Are they 600 like the N54 cats?
BMW X5 35i: Boopie Exhaust & Intercooler, K&N Drop in Filter, JB3 (3+ psi)
2013 Dodge Challenger R/T: CAI, Catch Can, Custom Exhaust, Headers, 87MM Throttle Body, Diablo Custom 93 OCT Tune