One problem related to catalytic convertor has been reported for the 2008 Ford F-250. The most recently reported issues are listed below.
Engine rev's up on it's own. I discussed this with a dealer and was told this will happen when the catalytic converter cleans it's self. The first time I was in a parking lot and not in any danger, the second, third and fourth I was driving in traffic but I had control of the situation but the last time I was in my garage and almost drove into my house wall this is very dangerous! I think this needs to be corrected. I still have not gotten any reply over the loss of steering I reported about 2 months ago on this same vehicle, this is also a dangerous problem!.