need tech help
02 3.8 mustang, has an intermittent miss ( but not steady) under mid to hard accel. Did a complete tune with plugs wires, all filters and problem returned after a short time driving. I then found a bad wire and replaced all wires with another new set, still same problem. I had a check engine light come on some miles later with a PO402, high EGR flow code. I replaced the presure sensor and reset the check engine light with no other codes found. The car appeared to run normal for approximately the first 20 to 25 miles then the same problem returned. It doesnt do it 100% of the time but it is mostly always present.