I have a 2000 Blazer 2dr. 4X4 5-speed with 75,000 miles on it. When I am at a comstant RPM while driving every once in a whil I will get a moderate hesitation. I have also noticed it during steady acceleration too. Replaced MAP sensor, fuel filter, cap & rotor, plugs, wires, cleaned throttle body. I noticed it about a month or two after I installed a K&N cold air intake on it. Looking for any help I can get

 

Clean your MAF, if the K&N had excess oil then the MAF will get coated with not only the air cleaner oil but dust and dirt to....primary cause of these symptoms.

 

you might want to check that the EGR valve is clean also.

 

Could be a EGR valve sticking as stated by Chevy Lover. Remove it and give it a good cleaning. You may want to try some SeaFoam too.

 

Replace your fuel filter.