Sorry it was late when i posted my frist post cel was on for a little time before i take it to ford and that is when i get all the codes all but 1709. Did all the work to fix the problem drove the car for about a week cel back on for iac replaced it. Drove a couple of day light on agian take it to a friend check codes 420 and 1709 was in the bank. But i just replaced those o2 so we check all 4 os to see what there were down dsterm os in bank 2 was bad is i repalced both. Drove the car for 2 days lihgt back on code420 i think that code 1709 was just a computer fart. But now the only code is that fing bad cat code not good . Is it possible that with the free flow exhast will that trip 420??? also should i replace both bank 1 & bank 2 cats with the ones from msds or the ones from ford?? Thanks i hope that clear up what is up with my tour later s