i replaced my ddrp with a fass hd 150 and my truck runs a lot better. the only problem is it still feels laggy and every once in a while it feels like it falls on its face and has no power or throttle response. any input will help. fuel pressure doesnt drop at all when this happens and its running around 21 psi constantly

 

Reset your apps

 

i have reset it. i tried to adjust it but its a tad under what it calls for. could this be the cause of laggy throttle and rough idle?

 

If its way out possibly but if its out a little id say no. I adjusted mine bout a month ago and i would say by now its out a lil again.

 

so its most likely a vp?

 

Well Its not your LP and your APPS is Fine. Either ECU OR 44

 

i put a new fass 150 in about two weeks ago and it helped a lot. what could be wrong with the ecm?

 

If it helped when u added the fass then its a fuel issue not a control issue. So I would say its your 44 then

 

I changed my vp and put a fass150 in and replaced the apps sensor and still get dead pedal anyone know what it might be

 

When you say u have a dead pedal, please explain what u mean, for instance, does the truck run fine then sometimes when you push on the pedal theres no response ? does the engine idle fine all the time? can pin point when this conditions happens ? like climbing a hill the engine has no response to the pedal or is slow to respond to pedal but flat ground it runs ok ?,
A bad boost sensor can cause a sluggish engine, a faulty waste gate on the turbo can cause the engine to run sluggish, If you have a boost fouler installed i have seen them go bad and cause a really sluggish engine,
If you have a aftermarket tuner disconnect it and see if that corrects the problem,
being as you already replaced most of the common parts that fail, how about checking all the grounds and plug connections etc, Do you have a good obd2 scanner to plug in and look at some of the operating parameters ?
Good luck Rich