Idle question

[afbryanwv]

I have had my Gryphon for a month or two. Everything has been great. I'm just curious if I should be concerned about this problem I have experienced twice. Twice when I have come to a stop the engine seems to idle lower around 475 instead of 530-550 I believe. It seemed to sputter a little bit like it was going to shut down. Before I even installed the Gryphon, I cleaned my MAF and throttle body. The fuel filter was also changed. Other than those two little hiccups the truck has ran fine. It has only done this on the custom tune and not the canned tow tune I used while I waited for the customs. I don't drive it much due to driving a work van majority of the week. Anything I should be concerned about or a tune issue? I'm using the 87 perf tune. My truck is a 2006 ford f150 5.4L with 68k miles. I'm pretty busy with work, so I may not respond back right away. Any input is appreciated. Thanks.