2002 X Type,CATALYTIC CONVERTER either needs replacing or rebuilding every few days the check engine light comes on, and when scanned the converter codes pops up after hitting clear it willturn off the light for a few days before coming up again, what should do? Dealer wants too much $, and I am not sure if the warrenty is still good, how do I find out if ford will/can change it for free, it is less than 8yrs old? I changed all my sensors up and down streams but I am still loosing in gas consumption, down from 22MPG to 17.2MPG.... Maybe someone knows where to get used one for a really low price?