2004 Multiple Issues, can't find source
 

2004 Freestar S - 199,000 miles - Starts fine every time and runs normal for the first 20 or so minutes. The longer it stays running the more lag there is in shifting gears when accelerating, especially from first to second. About 60 mph+ van begins to shake, feels like engine is shaking. Was shifting between reverse and drive and its a very rough shift, my roomate noticed upon shifting the whole engine was moving forward or backward. Other day car shut off while driving. Checked the PCM this morning and could not detect any water damage or corrosion of any kind, as I heard most of these issues are PCM related. Did get a diagnostic and only code that came up was a stuck valve and mechanic said it might have just been stuck but if it keeps happening may need to replace EGR. I am too broke to pay a mechanic so what do I need to be checking? I am aware of the transmision torque converter recall, but not sure if that is an issue besides when the car shut itself off while driving. Any advice is much appreciated!

My wife's van had a lot of these same symptoms you describe. Since these symptoms developed, I fixed 3 problems. Torque converter, engine and transmission mounts, and coil. After the recall work was completed, the transmission shifted nice and smooth, and even smoother after I flushed it a couple months after the procedure. But it still clunked into gear when going from P to D or R to D. That's when I found the broken engine mount. Kind of surprised the dealer didn't catch that. So, I replaced both engine mounts, trans mount, and stabilizer strut. One week later it started shuttering again and this time it tripped the CEL. Code come up as misfire. Replaced the coil and its been great ever since. Another thing I replaced shortly after we purchased the van a few years ago, was the cam synchronizer shaft. That created a lot of the same symptoms that you describe as well. Hope this helps.