sonoma loading up

I have a 1994 6 cyl 4.3 liter automatic sonoma. When i drive the truck it seems to load up and shake a bit. It does this mainly when i try to accelerate quickly. We recently replace the egr valve and the thermostat. That didn't help to much. The mechanic said there was a lot of carbon on the egr valve so i decided to replace because we have cleaned it many times before. The problem could be in the exhaust from all the carbon build up. Any suggestions.

Replace your CPI injector and nut kit.