Easy guys! I have been talked down to worse than this before. Yeah, I thought it was kind of a rude comment when I first read it but shrugged it off as Bluegrass maybe having a bad day. Just a note to you Bluegrass, I searched for a definition of that code for a long time without success. It wasn't until I copied and pasted into the search bar what you had typed before I finally found that code. And then, only 3 links were provided. Just because it seems like a silly question to you does not mean the person has not looked for an answer. He!!, I even went to a sight that (supposedly) has Ford techs that answer your question for a fee. I paid 9 bucks for this guy to tell me that there is no such thing as a P3401 code and that it was probably a P0401 code and told me to replace my DPFE sensor. This was before your post and I have since ordered one as I needed one for my Winstar anyway and they both use the same sensor and is a known issue with Fords.
My point is, you obviously know what you are talking about and provide useful information but if you feel the need to inject condesending remarks to make your point, send your comments in a PM so as not to deter others from posting here.
jbrew- Thanks for watching my back but don't let it bother you. I appreciate the help!

 

yeah I got one of them too about my tranny!!

 

must work for a ford dealer or some sort.