In a jar with a lid, combine the vegetable oil, apple cider vinegar, egg substitute, garlic powder, paprika, poultry seasoning, salt, and pepper. Close the lid, and shake to blend. Place chicken in a shallow glass baking dish. Pour about 3/4 of the marinade over it, and reserve the rest for basting. Cover chicken, and refrigerate 8 hours, or overnight.
Preheat grill for high heat.
Lightly oil the grill grate. Place chicken on the grill, and discard marinade from the dish. Cook the chicken for 10 minutes on each side, or until juices run clear. Brush reserved sauce onto chicken just before serving.