Ok so me and some friends were going camping yesterday and after I filled up my tank, the truck wouldn't crank. No dash lights came on or anything. It cranked the second try, so I just forgot about it. When I went to pick my friends up, I did it again, but this time it took a few more tries. Well I did what any prideful man would do and drove it 100 miles anyway(no CEL at the time btw) about 5 miles from our exit, it went into Engine Failsafe mode. It still ran so I coasted into the ford dealership and had them drop us off at the campground while they worked on it. So they said it was a throttle body issue. But on the way home, we got 4 miles at 70 mph and it went into EFM again. So I had to turn around and they have checked the body they'd put on. Well got the same distance and I did it again, so I made them come pick it up and got a ride back home. What could the problem be? The CEL continues to point to the throttle body.

 

There are many reasons for your truck to go into "Limp Mode" but I'd look at the exhaust system specifically the CATS. They may be plugged and overheating the exhaust gases.

 

At 130k mine (2005 5.4 l 3v) would go into fail safe , pointed to throttle pos sensor, changed it first. Then it did it several more times , cleaned throttle body real good . Found out I had the trouble some version of throttle body . Bought new version off ebay-- new with brand new tps on it , has been good since then , 200 bucks for whole thing and its not hard to do . Your labor costs are higher than that .
Suggest you list codes and miles as well as truck details . No telling what the dealer actually put in there . I got your 2004 year and engine size off your profile.
I have changed plugs twice , replaced all injectors(oem Ebay) at 140k at a cost of 200 bucks, beats breaking down and getting charged at least 200 for each everytime one quits. If the cops start failing i will change them all. You tube helps a lot with how to's.

 

Manufacturer Part Number: 8L3Z-9E926-C

Warranty: Yes Interchange Part Number: 8L3Z-9E926-B Brand: OEM Genuine Ford Parts

Other Part Number: 8L3Z-9E926-A

 

Update: it was never my throttle body, but rather a busted AC hose. It leaked onto my fuse panel and caused the CPU to shut down the throttle.