First of all the vehicle is 97 f150 4x4 auto 4.6 with about 80 thousand miles. The problem start out as bad surging and the codes that were present were:

P1299 cylinder head over temp protection active

P0136 O2 circuit (bank 1 sensor 2)

P0156 O2 circuit (bank 2 sensor 2)

P1451 Evaporative Emission System Vent Control Circuit

Also the freeze frame data i collected off the code reader:
Fuel Sys 1 CL
Fuel Sys 2 CL-Fault
Calc Load (%) 65.88
ECT (degrees F) 194
STFT B1 (%) -0.78
LTFT B1 (%) 15.63
STFT B2 (%) 0.00
LTFT B2 (%) 15.63
ENG RPM 2130
VEH SPEED (MPH) 37

After a number of trials clearing the codes while driving and trying different things i found that Fuel Sys 1 will change to OL-drive only under WOT and will return to CL under normal driving conditions.

Now the problem has progressed to stalling and it will often not start again after without several attempts.

Also there appears to be an audible clicking sound coming from under the hood only when the vehicle is acting up.

I have checked the coolant level and it appears normal as well as the temp gauge reads normal when this occurs. The fuel filter has been changed recently. I have also checked for vacuum leaks and fixed any that were apparent. Don't know what else to check. Any help would be greatly appreciated.

 

behind the intake ,atop the trans there is a 90 elbow vacuum hose, you cant see it without leaning over the motor,this seems to be a common cause of the problem youre describing. similar codes came up on my 98 5.4 and this was the cause.good luck!

 

checked that paticlular piece and it appears fine.

another update.....
Also i figured out where this clicking sound was coming from and it appears to the PCM relay clicking wildly in the power distribution box. I changed the relay and it still acts up. Where do i go next.........................

 

the 90 elbow on mine had ruptered in the middle ,couldnt really see it until i took it off. the reason the codes po136 and po156are showing up is that the o2 sensors are trying to compensate fore additional air and cant adjust the computer properly.it could be the egr but i doubt it ,maybe fuel injectors need cleaning or air filter.

 

upon closer inspection it is the fuel pump relay that is clicking wildly when the vehicle acts up.

checked the fuel pressure today and it is 37 psi ignition on not running and 30 psi running