My brother had a similar problem like this in his grand am. He would do something minor to it, and the car wouldn't start for a while, than it would magically run fine. Ended up being the cluster in the dash shorting out, and throwing codes everywhere.. Double check your wiring to your plugs, check everything electrical near the area you worked on your car. I'm in a computer class, and my teacher always say's double check everything before you turn it on.