please help engine hesitation

[rangerrager]

hey guys please help
when i floor it on my truck it like hesitates and surges and will not go over 2000 rpms ....can anyone help me on this..not sure what do do..i just put in new spark plugs so i am assuming thats not the proble...less that 100 miles ago ran fine intill now

 

[Big Jim M]

Could it be the muffler or cat is almost completely stopped up? Does it whistle out the tail pipe? Does it idle rather well but not get rpm like it should? Does it simply seem underpowered like maybe you are towing a HUGE trailer?
Big Jim

 

[rangerrager]

hmm..well i know the muffler is not clogged up becasue i ordered a new exhaust so why i am waiting for my new stuff to come we cut holes in the muffler.lolol..but how do i tell if the cat is clogged...the truck idles like a champ..idles great..and i go go really smooth on the throttle i can get it going...once the motor is past 2500 its fine...but if i ffloor it from a stop and hold it down the motor surges and dooes not go overe 2000 rpms...i have no idea what it is..is this a clogged cat?

 

[rangerrager]

is it maybe a mass air flow sensor?