first this is a GREAT site
I have a 2007 f150 supercrew 4x4 with the 5.4liter and auto trans. I have 65,000 miles on it now and this problem started the very same day as i emissions test which is just a coincidence. and I am out of warranty.

After warming up the truck will jerk multiple times on steady throttle and a slight increase in throttle, on level ground and inclines, never on downhill.

i have a superchip programmer that came with my truck when i bought it new in 07, the code is P0300 and is a random multiple misfire with no specific cylinder tagged.

Seeing that it was random i decided to replace the cheaper parts first that would effect multiple cylinders first, so i replaced both Camshaft senors and crankshaft sensor, with no effect, i then replaced all 8 cops and spark plugs with no effect ( left the plugs in and took the cops back ) I have looked at every vacuum line coming off the engine for cracks and tears and nothing, i removed the entire intake system from the throttle body to the air filter and replaced the TB seal and cleaned and reassembled it with no effect.

so i decided to monitor my o2 sensors and noticed that B1-S1 and S2 and B2-S1 Change voltages dramatically from .01 up to .9 and B2-S2 stays steady at .742
I don't know if this is normal or not so at this point i am lost and open to any good ideas that y'all can come up with.

 

The front sensors are the ones that should be changing voltage constantly, more as the rpms change. the rears are just monitoring cat efficiency and do not change as much.

Have you cleared the code and if so does it come back? That is a tough one since it is random and the PCM cannot figure it out. Low fuel level is listed as possible cause according to Ford's DTC list.

 

yea, reset and it is back again within 10 miles during this time the jerking is still there. It ideals fine and accelerates fine from red lights, something else i noticed is it seems to only do this when the truck gets up to operating temperature and not while it has been sitting and aloud to cool off.
I always stay above a quarter tank on gas

 

hmmm have to think about this one. So it runs fine when in open loop but runs like crap once it goes into closed loop operation. No other codes come up? Might have to visit a mechanic that has a good scanner and look a little deeper like looking at the mode 6 data. Maybe someone else can offer some advice. I would double check electrical connections on everything you have touched lately.

 

just the one code P0300, i have actually triple checked every elec. connection under the hood,
Now i replaced the cam sensors But i wonder if the cam phasers could cause this problem