you have no "problem". i've dealt with this before. the hose under the runners is connected to a <1 lb device called your idle control valve. there should be a rubber doughnut supporting the idle control valve. if there isn't, this will cause it to move, which will pull off the hose, and put strain on the connector (possibly breaking it, like it has for you). your car came equipped with hose clamps on the hose that keeps popping off. if there aren't any, it is because someone took them off. simply replace the broken fitting, put hose clamps on all of the idle control valve fittings, put one on the broken fitting's replacement (so 3 total), maybe replace the elbow that goes to the air intake boot (so that you have a snug fit). do all of this, and your problem will not re-occur. the fact that this is happening is not indicative of high/low crankcase pressure or any other "real" problem, your car came from the factory with hose clamps on those fittings. the fact that it hasn't started to blow the hoses off sooner is only a testament to your good luck.