First off, calm down. Second I gave you something you can do in my previous post. You can pull the cats off (I believe the 5.4 has two cats like the V10 but I don't know for sure) and do an inspection of each. If either one is clogged you will be able to see right away. If you don't want to pull the cats (and risk voiding your warranty) then hook a vacuum gauge up somewhere on the intake manifold. Start the engine and let it warm up to normal temp. With the vehicle parked record the vacuum at idle. Then quickly press the throttle to wide open and then quickly snap it shut. Do this three times and record the vacuum at each wipe open moment. Do it a fourth time and record this vacuum reading. If the forth reading is more then one in-Hg lower than the reading at idle this can indicate an restricted exhaust (like a cat but could be a muffler).

Now you can save yourself all the hassle and take it to a Ford service department. I am not sure why you think you have to prove something first. I can understand if you already taken it in and they blew you off but have you even let them try? I would at least take it in, describe the problems and give them a chance to fix it.

 

Agreed, take that sucker in and let them worry about it. You paid all that money for a new truck, let them earn it. If you're just wanting to see if you can do it yourself, or whatever, you'll have plenty of time for that down the road. If the dealer is any good with customer service, you can talk to the mechanic who worked on your truck and pick his brain on how he got to whatever conclusion he go to.

 

not looking to do it myself , looking for info that when it goes into dealer on monday that they dont try to bs me. it gets my horns out when somebody is looking for info and then u get sarcasm from someone. it be different if i knew the individual and your just joking around. great site , alot of info and good people on this site. enough said !