1Spray 4- to 5-quart slow cooker with cooking spray. In small bowl, mix chile pepper powder, oil and salt. Rub mixture over pork; place in slow cooker. Sprinkle with poblano chile. Pour salsa over top.
2Cover; cook on Low heat setting 8 to 10 hours.
3Remove pork from slow cooker to cutting board. Shred pork, using 2 forks. Return pork to slow cooker; mix well.
4Using slotted spoon, spoon about 1/2 cup pork mixture onto each warm tortilla; top with about 1 tablespoon each guacamole and sour cream. Fold 1 side of tortilla up about 1 inch over filling; fold right and left sides over folded end, overlapping. Fold remaining end down.