I just put a performance muffle on my 4runner and I've noticed better performance at about 3000 rpm and above where it really pulls well. But when I first start up my truck in the morning, there are 5 mins where you have to put the pedal to the floor to get any forward motion. Almost feels like it isn't getting any air or fuel or something like that. Has anyone else experienced this with a new performance muffler? Would this have anything to do with the fact that I went to a 2.5" muffler from the 2" factory pipe? I've gotten used to it but my wife was driving my truck and though something was seriously wrong with it. Any suggestions to help with this? Thanks in advance!