Nissan Repair: hesitation, haynes manual, nissan frontier

Question
I bought a used nissan frontier with a 03 vg33e engine. Engine hesitates and shudders in the 2000 - 3000 rpm range and is low on power. Past this range it gets up and goes.
I have cleaned the MAF sensor and seen some improvement. The knock sensor, I am told, is new.

Answer
Devon,

If the hesitation comes at a specific speed you will need to check the throttle position switch first.  Get a Haynes Manual for the values for your specific year.  Have the timing checked to make sure it is correct as that will cause a stumble too.  Email me back with what you find.