Put the chicken in a large stock pot. Cover it with water. Add 2 celery ribs which have been roughly cut. Add the carrots which have also been roughly cut. Add the cut onion, salt, pepper, and garlic powder. Bring to a boil and cover. Reduce heat and simmer for 45 minutes. Remove the chicken and allow to cool. With a hand blender, puree the vegetables in the stock. Strain stock through a strainer into another stock pot to remove any bits. Add the box of stock to the new stock and put aside for later.
In a medium bowl, beat the eggs. Add the stock and oil mixture and beat. Add the salt and pepper. Add the matzo meal and blend. Allow to sit on the counter for 20 to 25 minutes.
Remove the chicken from the bones and dice into small pieces. Put aside with the rest of the diced celery and diced carrots.
Bring the stock to a rapid boil. With a tablespoon, scoop matzo ball mixture into the boiling water 1 tablespoon at a time. If you want to roll it in a ball, oil your hands first to prevent the mixture from attaching to your hands. The balls will pop to the top of the stock. Add the chicken and vegetables and cover. Simmer for 10 minutes. Add the noodles and cover for another 5 minutes before serving.