I have a 1997 Tahoe with 220k on it that has been having a reproducable misfire or something. At 1700 rpms it will drop about 200 rpms and have slight hesitation. It only does it seemingly as it moves to a higher gear as throttle pressure decreases. It does not do it accelerating through 1700. It hits a little harder at highway speeds and happens all the time. Other than that the truck runs fine, is throwing no codes, and had no stored codes. Did a full tune up but the problem persists. Any ideas where to look next?

 

The distributor gears wear on these engines causing this,it could also be a dieing spider injector they make an upgraded version of it amazon,rock auto and parts geek have good prices on them,try some techron and some seafoam in the gas tank to see if that helps,have you checked fuel pressure?