any check engine codes? It would not suprise me if it spit out a spark plug. I would check all the plugs make sure there is no black exhaust soot all over them.

 

How many miles? Sparkplugs are definietly an issue. They break off during removal.

Looks like you handled most of the common problems with that motor. Also check the COPs- coil over plugs.

 

Be Sure to Read this!!

http://2coolfishing.com/ttmbforum/showthread.php?t=459665

 

Plugs were changed, I checked for a IAC and was told the 2007 does not have one. Does the 2007 have a IAC ? That stands for Idle Air Control

 

Could be the coils. It could also be the cats. There are two cats on the 5.4 with O2 sensors on either side of them. I believe one of the O2 sensors is actually mounted in the cats. I had trouble with mine after I had the cats changed. Ended up having to change a few sensors too.

 

I was going to suggest O2 sensors or MAF. My guess would be O2 sensors since you just replaced the cats.

 

check fuel pressure?
Clean MAF maybe?

 

07 f150 doesn't use an idle air control valve, it has an electronic throttle body. it will usually have a check engine light or wrench light. since plugs have been changed, i'd have fuel pressure and fuel quality checked. i agree with racer x, it doesn't hurt to clean the mass air flow sensor. check under the air filter to make sure there's no restrictions

 

If you got aftermarket plugs I would pull and check em. They are bad about the porcelain cracking when installing ang giving problems like that. I would buy plugs from a dealer and retest. Let us know what fixes it

 

Truck

Sounds like a dirty throttle body or a bad throttle position sensor.

 

Tell the mechanic to keep it and get a Chevy!!! Sorry I couldn't help myself.

 

fuel pump?

 

all the plugs/fuel injectors/wouldnt go out all at the same time . put a pressure gauge on the fuel rail there is a schader valve just for this and watch the pressure . i would also watch the voltage to the ignition

 

i agree with JV. its not above the cats to be blocked off again, choking the motor out. get rid of them, put some MIL (missfire intermitent light) eliminators plugs in and be done. yes it will still pass emissions.
i have also heard horror stories about the ECM over fueling the cylinders, causing hydro lock or sending a piston into the oil pan. possibly check the oil to see if there is a gas smell to it. just my 2 cents.