So this truck is a 2002 escape with the 3.0. I went to autozone to check the codes and it threw out like 3-4 codes related to a vacuum leak and cylinder 1 misfire. truck runs very rough. when idling, it wont rev past 4000 rpms. I already read the thread on how to change the spark plugs and cop. What I need help on is where to look for this vacuum leak. Thanks in advance.