Wazzup again fellow evo owners. I just need your input on a problem that my 2003 evo VIII has been having occasionally since October of this year. I notice that when accelerating normally, my evo VIII's engine seems to hesitate for a second just about when I release the gas pedal and depress the clutch to go the a higher gear. Note that this happens around/just approaching 3K rpm and from 2nd-3rd gear or from 3rd-4th gear. It does not do this often though. It just happens every now and then AND it seems to appear more when going up hill (like accelerating on an on-ramp entering a freeway). What do you think is the cause of that bit of engine hesitation? My evo had just broken 170,000 miles on the odometer.
It is important to note that I just had the EGR valve/solenoid, water pump, timing belt, spark plugs and oil changed recently plus had a throttle body/injectors cleaned recently as well and it is still doing the engine's hesitation. Thanks in advance for your take on this issue.

 

Have you done a boost leak test? Are your spark plugs gapped correctly?