In a medium saucepan, bring 6 cups of water to boiling. Remove from the heat and add dried guajillo and Chile de Árbol peppers. Submerge peppers. If more water is needed add hot tap water to cover the chilies. Cover and let stand for 15 to 20 minutes or until the chilies have softened. Drain the chilies and remove the stems and seeds. Discard the stems and set the seeds aside.
Add the chilies, tomatoes, garlic, onion and 1 teaspoon coarse kosher salt to a blender. Puree until smooth. Season to taste with kosher salt.
In a large skillet over medium-high heat, add the oil and heat until shimmering. Add the shrimp and cook, turning once, for 1 to 2 minutes or until the shrimp is light pink. Using a slotted spoon, transfer the shrimp to a bowl.
Lower the heat to medium. Slowly add the chili mixture to the skillet. Cook, stirring, 5 to 7 minutes or until the sauce is bubbling. Season to taste with salt and pepper. If the sauce is too spicy, add sugar, in ¼ teaspoon increments, until the sauce is to your liking.
Add the shrimp to the sauce and heat, stirring, 3 minutes or until the shrimp is heated through.
Serve with lime wedges, if using.