Thanks for the various suggestions on places to go for lunch in Norwalk. I ended up being taken to Taco Rico in the Firestone Plaza. This is a very good Mexican place that is quite busy at lunch time.
I had a combo plate with a cheese enchilada and a taco al pastor with rice and beans. Excellent. Dining companions had hard tacos and every one was very well fed and happy. Lunch for three was under 20 bucks. Homemade chips were excellent, but the salsa was nothing special.
If you find yourself in Norwalk this is a good place for Mexican food.