even a pcIII or PCV won't cure the popping. Technically the popping was always there, you just couldn't hear it with all the stock exhaust. The ais system introduces fresh air into the exhaust so that fuel that didn't get burned in the cylinder can be burned off and make the exhaust cleaner. Even gas needs oxygen to burn, eliminate the oxygen supply and it can't burn. The easiest way to stop the biggest part of it is take the top off the air cleaner box. there is a hole on the left side of the filter, you can see the hose come off the bottom of the air box and go to the ais system on top of the head. fing a bolt or something that will just fit down in the hole, cover it with silicone and plug up the hole. that's where the ais gets the fresh air from. taking off the whole system is better for aesthetics but this will do it. it's still going to gurgle but the loud popping should be solved.