2001 Hyundai Tiburon Rough Running

I have a 2001 tiburon, 4cyl auto. It has a check engine light for a (P1124-manufacturer control fuel air monitoring), and also (P0301-misfire) and (P0300-multiple cyl misfire). The cars runs rough at and idle but only in park and neutral, somtimes drive but not usually. Cars run great going down highway and doesnt skip when fullthrottle is applied. Doest skip even going 35 or so. Just runs rough on idle. I can here what sounds like to be a loud vacuum leak but ive spayed a flammable cleaner all around it and it never reved up any. Ive also checked all connections to TPS, MAF, and others nuthins loose or corroded. The car has never stalled or reved up on its own. The car has always run good and recently I noticed what I think to be a loud vacuum leak and ever since that has started its run bad at idle, but its weird because it runs really good driving it. It does need a tune up but again if it was skipping it would run bad all the time and it wouldnt have as much power, its def running on all cylinders while drving but not at an idle but, wires are good checked resistance and came out fine, could be replaced but nothing to cause a skip, im thinking the misfire code is only on because it was running rough on one day and did skip but hasnt since and code stayed in the computer. An ase tech told me too fix the skip first but like I said it runs too good while being driven to cause a problem at and idle. I really need to see the live data and check sum voltages but till I do that im stuck.