Answer: Spectracide is an insecticide, not an herbicide so what you applied effectively killed any insect populations in your yard but it isn't formulated to kill the weeds - unless you used a product called Weed-Stop by Spectracide. You didn't specify that particular product so I don't know if that's what you actually used. For broadleaf weeds such as dandilions, you'll want to use an herbicide containing 2,4-D. If your problem is dandelions, you can use something like Scotts Turf Builder with Plus 2 Weed Control. Or, you can spot-kill weeds when you see them with a weed-killer such as Ortho Weed-B-Gon Max Weed Killer For Lawns. It should take care of the weeds and leave your grass unharmed.
Best wishes with your lawn!
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