1. Preheat oven to 350°.
2. Combine pecans and canola oil in a small bowl; toss well. Place pecans on a baking sheet. Sprinkle with 1/4 teaspoon salt and sugar. Bake at 350° for 5 minutes.
3. Preheat grill to medium-high heat.
4. Combine 1/4 teaspoon salt, 2 tablespoons olive oil, vinegar, and 1/4 teaspoon pepper in a large bowl, stirring with a whisk.
5. Brush pork with remaining 1 1/2 teaspoons olive oil; sprinkle with the remaining 1/2 teaspoon salt and remaining 1/4 teaspoon pepper. Place pork on a grill rack coated with cooking spray; grill 6 minutes on each side or until a thermometer registers 145°. Let stand 10 minutes. Cut, crosswise, into 1/4-inch-thick slices.
6. Add escarole and celery to vinegar mixture; toss gently to coat. Place 1 cup escarole mixture on each of 6 plates; top each serving with 1/3 cup pears and 3 ounces pork. Sprinkle evenly with pecans.