Why does my truck start up then die right away?I had the catalytic converter replaced in July.My truck ran great ,for a week.I started my truck and then it died right away.I had replaced the fuel filter before the catalytic converter.Along with plugs ,battery,fuses, then a new fuel pump.I even got a new part from a local auto store.For the fuel relay thats on the passenger kick panel.It did the same thing.I don't know what else to do.I love this truck.What is causing it to die right away?