Make sure they are gud-n-tight (like a German virgin) and the connectors are well connected to the harness. Any air leak at all will cause a code. Make sure you didn't twist or crush the sensor wires as I believe there is an air tube for ambient air inside. Damaging this will cause a code. Like others have said, knowing what he code is will help. You can have it read at most any auto store, they just can't clear it. You might also find something more helpful in this thread:
http://www.camaro5.com/forums/showthread.php?t=193058