ok so i finally got around to geting my new intake put on. i have put a new carb on top of that too. Its a chev 350 with a edelbrock performer EPS intake and a holley 570cfm street avenger carb. when i went to flash it up it started but had a popping out of the exhaust. it runs fine but it has a loud pop every 2-3 sec. what could cause this?