About the backfires
Definitely got them here as well, first time I heard it I thought the rear end was exploding (I'm exaggerating, but it was definitely loud). NOTE: Since I switched to midgrade/premium those issues have disappeared. I think it has something to do with the ECM trying to prevent detonation from using 87 or "bad gas". I'm sure I'm wrong, this is just what I've read in other forums because I didn't make the connection to the exhaust at first. Computer will supposedly retard timing and even reduce output slightly if it detects lower octane with its knock sensors.
About the exhaust.
I am 99% that I'm returning this exhaust. At idle and VERY low RPM the exhaust is great. Anything other than a "small" acceleration leads to a sound I don't like, just doesn't seem right coming from the truck. Also, there are bad exhaust leaks coming from almost every clamp provided to me. Again I am not a small man, and have put quite a bit of torque on the bolts. I still can't get the hissing to stop, nor could the exhaust shop...
Mild acceleration is just bad honestly, and that's how I drive. WOT is a little raspy but honestly doesn't sound too bad. Idle is great. The mid point is too sports car-ish. After an evening with a friend he finally proclaimed "350Z!" as he had spent the last hour trying to decide what the truck sounded like. I guess I just have to stick with stock
I think the biggest let down is this--As others have stated it sounds nothing like the video. Honestly the exhaust isnt bad but it's definitely not what I was expecting, and I think it's kind of soured my opinion on it.