1. Whisk together 1/4 cup soy sauce, cilantro, 3 cloves of garlic, brown sugar, vegetable oil and the juice of one lime in a bowl for the marinade.
2. Place the pork tenderloin in a gallon-sized zip-top plastic bag. Pour the marinade over the pork tenderloin, reserving about 1/4 cup of the marinade in the refrigerator for later use. Close, and refrigerate for at least 30 minutes and up to 4 hours.
3. Meanwhile, cook the pasta according to the package directions. Whisk together the juice of one lime, 2 cloves of garlic, peanut butter, hot water and soy sauce for the peanut sauce. Drain the pasta once cooked, and toss the pasta with the peanut noodle sauce in a large bowl. Add more soy sauce if desired.
4. Heat grill to medium-high heat. Remove pork tenderloin from the marinade, discarding the excess marinade. Place on grill and cover grill. Cook, turning occasionally, until browned and instant-read thermometer inserted in center of pork reads 14 5°F, about 15-20 minutes. Transfer to carving board and let stand 3-5 minutes.
5. Transfer the grilled pork chops to a cutting board and let rest for 3 minutes before slicing against the grain.
6. Pour the reserved marinade over the sliced pork before serving and serve over the peanut noodles.