i don't know what the problem is im not getting a check engine light i don't know if the light even works when i turn on the truck it only displays the battery indicator, abs, 4x4, oil but i don't see a CEL. when i push the accelerator down hard its like its flooding the engine rocks and stutters bad idle or in gear and when in gear the truck won't speed up, if i throttle down slowly it functions like it should almost but when if i drive and do this i can get to about 30mph then it starts stuttering and stalling. before this started happening i had poor acceleration response and when i got to about 65mph the truck would shake a bit and sounded like lifters were rattleing and only when in gear and i would romp on it or going up hill. and would occasionally stall out and i would have to pull over and let it idle down then i could take off and get up to speed again but 2 fridays ago the truck stalled down and i can't get over 30mph anymore.

i replaced the throttle position sensor already, i don't know if its the DPFE sensor or the map sensor.

 

Without knowing what you have other than a 97-03, I would start with a fuel filter. Forget about a MAP sensor or the DPFE that you do have.
Why did you replace the TPS?

 

i have a 1998 4.6 Triton i replaced the TPS because a few months back i started to experience the lost acceleration i came to the forums and someone suggested that it might be that sensor, when i took out one of the bolts to check it cracked so i needed to replace anyways.

 

i changed the fuel filter still runs the same push the throttle down and stalls and stutters. and if i lightly push down i can accelerate very slowly. get up to 30mph and thats it start to try to go faster and the truck shakes

 

Can you rev the rpms up with the truck in park? Rev up to 3k with no stumble?

 

yes if i press down slowly on the accelerator if i stomp down it stumbles.
i just took it out for another test run and when i accelerate to 35 as soon as it hits 36 it drops my RPMs drop and i drop down to 30 with my foot on the gas if i push harder nothing if i let off and press down slowly it will start to go again

 

Why not get the CEL to prove out, at least then you might get a code.

 

the problem is i don't know if that light is working or not. it doesn't come on when i start the the truck and when i first power on the truck i don't see it illuminate with all the other indicators, basically ima go down today though and buy a diagnostic tool i know i can use the ones at the auto part stores but ima get one just so i have one on hand from now on.

 

Ok, the next suggestion that I have is to pull the sparkplugs and look for any signs that would tell you that their is a problem with ignition.

As for the CEL light check the fuse for the cig lighter.

 

i replaced the spark plugs yesterday they looked like normal wear nothing odd about them just dirty