same symptoms as op for the last 15k miles as soon as I went catless dp's. I'm jb4, meth and dps...been burning about a quart every 1.5k since I modded. About to throw on some rb's and see what that does.
07 335i sedan AT 414rwhp/446rwtq
jb4, raceland, dci and meth...
12.06@117 with a 1.91 60'