1994 Chevy Blazer K1500

Hey im new here so take it easy on me. I have a 1994 Full size chevy blazer with 276K. Just changed 02 senor which helped my problem a little. Ok when im goin in reverse, and i let off the gas, it sounds like the motor is ready to stall. Tach drops off, and you can hear the individual pistons firing. Almost like a Top fuel dragster. It also happens when the truck is warm and lets say your pulling through dunkin donuts and your goin real slow and you take a corner and you give it only a little gas. Please help!

Anyone? Anyone?

is the truck fuel injected or carb?

Fuel injected TBI. Im changing out the EGR and vacuum lines this weekend. Already changed PCV and 02 Sensor.

Anyone?