About a month or so ago I installed a set of 6" Bullhorns on my truck. The other day I was walking around behind the truck and noticed and odd sound. The exhaust seems to be emitting a "chirping" or "squeeking" sound from the stacks. It almost sounds like a slight belt chirp. I have checked every inch from the turbo back to make sure nothing is loose or vibrating against anything. It does this at idle, however, under acceleration I have noticed an almost train whistle sound from the stacks. I thought that might have to do with the AFE Stage 2, but I just can't figure out the chirping at idle. Anybody have any ideas???

 

Thats the turbo whistle, lol. Very normal, and thats the sound we all love so much. Ur AFE intake just amplifies it to. The turbo has a silencer ring that u can take out really easily to make the whisle even louder.