2008 6.7 (two different trucks I have seen this on) stalls sometimes when you put it in reverse. If it does not stall completely, it will drop the rpms significantly low and barely idle when going to reverse. Loaded a tune on one time on one of the trucks and put in reverse and it would immediately die. Did a new full flash and now it will not stall completely or die but it will drop the rpms real low like it is going to die but will not. This is the same exact tune loaded both times. Have any of you seen this? Thanks