My corvette seems to have random power drop out and chuggling when trying to accelerate at any rpm below and up to 2300 rpm. In the lower gears this is not quite as noticeable as you climb in revs too quickly to pay much attention to it. Its very noticeable in 6th gear at freeway speeds when you try to accelerate at anything more than 10 to 15 percent throttle. If you push the throttle hard enough in these ranges you can sometimes even hear a shake or a knock even. I've had mechanics tell me to simply not drive at those rpm's because "the car wasn't made for it" which I find hard to believe considering the car has a One to Four feature on its transmission and the fact that 6th gear would only be usable at 90 mph if I followed that advice. I have had this Corvette for 2 years now and this problem has been present for almost all of that.

Here is some info on the car if it helps. It has 55k miles, new battery,new O2 sensors, egr valve, egr vacuum solenoid, fuel pump, fuel pressure regulator, air filter, spark plug wires and spark plugs properly gapped, and injectors cleaned and functioning properly. Fuel pressure reads correct and holds pressure. It's stock other than aftermarket catback exhaust. I have dyno charts also showing the car has maintained its horsepower and torque well over the years with 308 HP and 348 ft-Ibs. Has never thrown any codes with the exception of "slow o2 response" which it threw before and after the o2 was replaced but has not thrown that code in over a year though the problem remains.

Sorry for the long winded first post but I am losing my mind trying to make this car great again. Any help would be greatly appreciated.

 

One more bit of info I left out. I took this car on a road trip of about 1k miles when I first got it and experienced none of these issues whatsoever. The only difference I can see between now and then is that the AC worked then but has since leaked out so that it no longer functions but I do not turn the climate control on at all these days.

 

The 92 Vette I just picked up seems to do the same thing. I opened the hood with it idling the other night and could see several sparks from the plug wires arcing at several points. I see you state you did plug wires, but the way these things run through the accessories I can see them being an issue. I put the scrunchy electrical plastic wire wraps on the first 10" of the plug wires on the driver side as those route right through the engine accessories. I also put about 8" on the passenger side as it does the same. My car was missing one of the wire brackets that bolts under the valve covers and I lost one in the process (I'm still working on this). I still need to get now 2 of those brackets, a 4 prong clip and should be good. Are your wires routed perfectly tight using all the clips? I'd suggest looking at the engine with it idling in the dark to see if you have any arcs.
The next test would be a vacuum leak test. You can try spraying water with a spray bottle over hoses, injectors and other areas where there are vacuum ports. If you have a vacuum leak the engine idle will change when it sucks in the water. You don't need much, avoid spraying the opti, and make sure to dry off electrical connections. You could use carb cleaner too, but it can damage paint and is harsh on plastics. Another method, but you need equipment for, is a smoke test. I bought one off ebay for about $50 and have used it a few times. You tube is a great way to find out how to make one or use that.