Well the past few months when I let off the gas at say ~2000RPMs it will drop down to about ~1000RMS or less and jump right back up to were it was and start coasting again...but not everytime. When the rpm's drop I can feel the truck slow down like as if I hit the brakes or something (it pushes my body forwards some).

This morning I hit the gas too hard and it down shifted and went up to about 3500 rpms. Then it was doing it really bad. And i hit the gas again and it started sputtering and a knock ever time the truck would try to go forwards, it use to do this a lot! But in the past it was way worse, the knock was loud and it wouldnt do anything but sputter and slow down when I hit the gas. I ran a can of seafoam and it fixed the sputter for good while. It sputtered again and I put in another can of seafoam...fixed it...but now its doing it again and this time theres the problem with the rpms dropping significantly on decelaration too.

It wasnt doing it this afternoon but i went ahead and put in a can of seafoam and a full tank of gas. I dont want to keep putting seafoam into it, gas is expencive enough.

Oh and onetime I accidently floored the gas pedal in park instead of the brake to shift it into drive and after that it was sputtering. I think it hates it when i hit the gas too hard....

Its a 1999 Dodge Durango 5.2 4X4 with 240,000 miles
Thanks
Mechaniczman

 

Well the RPM issue could be a bad TPS, as for the knocking that could be a sticky valve.