It's fine. The pop you heard was probably back pressure in your exhaust
I too know the sound he's talking about..heard it one time my self when revving high. I have my rev limiter raised but sometimes it may pass it a bit on hard wot! That's when I heard mine..everything was fine and still is but I'm positive it wasn't back pressure. Sounded like it came from the engine..
GRABBER BLUE 2012 Mustang Coupe V6 Premium|Pony Package*
Performance: Airaid Intake, SCT SF3 Tuner, BBK Ceramic Shorty Headers, LethalPerformance O/R H-Pipe, FRPP Sport Axle-backs, JLT Oil Separator, DriveShaftShop Aluminum Driveshaft.
Suspension: Boss 302 Strut Brace, Steeda: Chrome Moly LCA's, Adj.UCA, Adj.Panhard bar, Ultra-Lite Springs, Pro-Action Shocks/Struts, Heavy-Duty Caster Camber Plates & Trunk X-Brace.
Wheels/Tires: Staggered 19" Forgestar Wheels with Nitto Invo Tires.