Low hanging fruit for a 3800 misfire is a spark issue. Like stated earlier... Move the coil associated with the misfire. If the misfire moves it's *probably* a coil. If the misfire doesn't move it's *probably* an ICM.

Part 1 -How to Diagnose Misfire Codes P0300-P0306 (GM 3.8L)

Part 1 -How to Test Ignition Coil Pack -Misfire Troubleshooting Tests (GM 3.8L)