Shaking until 2500 on tach then smooths out

[singedirk]

Shaking until 2500 on tach then smooths out
99 ranger 3.0 flex 4x4

Ive put new ujoints,ball joints,shocks.
New fuel filter tested pressure 50psi
new DPFE sensor ,o2,pcv(check engine light on)
checked for spark on coil and wires good
no vacuum leak
cleaned everything imaginable with carb cleaner iac,maf etc
any ideas?
This trucks has always done this and ive owned it for a year ive fixed everyother problem with it but this.It idles fine.

 

[srteach]

My 99 4.0 has the same problem. Compression check indicates a bad valve in my case. I plan on rebuilding the heads.

 

[singedirk]

check engine light was on before the new DPFE sensor.The plugs looked good.

 

[MAKG]

If it's STILL on, run the self tests and find out what it's complaining about. I've seen several claims that the right thing to do with ANY check engine light is replace the DPFE sensor. This is wildly wrong. It's a fairly common fault, but it's foolish to replace one without knowing it's actually the complaint (and preferably confirming a fault).