My 2005 F150 Supercrew 5.4 liter died on me yesterday. I was traveling at 35 mph on surface street when the engine died. The truck stalled and lost all power. Lucky I wasn't on the Freeway. Dealer report stated:
ROADTEST AND DIAGNOSED CODES; P2104, P0121 AND P2112. PINPOINTED AND FOUND ELECTRONIC THROTTLE BODY PHYSICALLY STICKING CLOSED. REPLACED ETB AND RETESTED AFTER REPAIRS....OK
Dealer said they have had other cases with the same problem but didn't seem concerned. I filed a safety complaint with the Highway Transport and Safety Board. This problem could cost you your life. Please beware.

 

My truck (05 F150 5.4L)is in the shop right now for basically the same thing. Truck stalled twice during deceleration, check engine light came on after the second time. Both times the wife was driving with our newborn,...not safe. Had the code read, it only showed the P2104 code. After research on-line and from other sources, I couldn't pin it down to what the problem is, so I took it in. (Faulty TPS, or PCM, etc..)

It is a safety concern when that happens. And from numerous other forums, it seems to be a frequent problem.

Tony- has the problem been fixed on yours? Any word from NHTSB?

Mike