This has happened to me twice now and the problem seems to fix its self. Today i was driving along and my car started to have a soft backfire nothing loud but you could feel it. The the rpms started dropping to around 650-700 it did that for about 10 sec. then just cut off. The starter would turn over, but the car wouldn't hold the start. Finally after about a min of trying to get the motor turned over it finally took and it is driving like normal again. This is confusing the hell out of me. I've checked my ignition system its giving spark, i've checked and adjusted my idle so that it idles around 850-900, and i've checked all my connections. The last time it did that, about a month ago, it was running the next day no problems and i had no idea that it was fixed cause i didn't do anything to it. Any help or ideas would be greatly appreciated. Oh and the engine isn't throwing any codes either. Here's a list of my mods if that helps.
B16A2
MSD Box, Blaster, Cap
Apex-i Vafc
DC Sports Headers 4-1 with custom 2.5 in exaust
AEM CAI off of a d16 (could that be a prob)?

One thing i haven't done is clean out my throttle body and intake, if it is too dirty will that cause this???