Yup this happens to me as well, but not as much as a before with the fidanza I used to have.  I have the new Tial Q Bov and love it, I can not recirculate it at all.  I'm on the Lex AFM and don't have any cats and it would backfire or pop alot in the exhaust.  I flipped on the EIDS feature on my HKS SAFR right before the car blew up and it stopped.  This feature knows to take out a little fuel when shifting I guess.