I have a 2002 mustang gt has a slight misfire,an slightly smells rich.Ive taken it to two different shops one says possible computer problems one says something to do with cam timing bit they really don't have a clue.So far I've put new injectors in,new plugs,cleaned maff,new pcv valve,new o2 sensors on drivers side,fuel filter,fuel pump.Was throwing a p0413 code but has seemed to have cleared on its own shop says it's not there,but a couple lean codes have popped up,,I'm at my wits end an have no ideas left,,could use some help