Look at you throttlebody. It is right to the right of the upper intake manifold (the big black peice of plastic on the motor. On the back side of the throttle body to the firewall you will see a black brackt with 2 wire cables attached to it. Make sure these are attached correctly.
There is also a recall as of April 2009 for you Grand Prix GT. Basicly during hard breaking oil could end up on the exhaust manifold and result of a fire.