Ok, the first thing I need to do is explain how the secondary air system works in your car.
When the engine is cold, emission levels are very high. The catalytic converter doesn't even begin to function until it reaches an internal temperature of over 400 degrees celcius. In order to get the cat up to operating temperature more quickly, your car has a system called the secondary air system. This system operates for about 2 minutes during a cold engine startup in order to pump oxygen into your exhaust stream, which in turn creates more heat in the exhaust, which gets the cat to operating temperature.
The system has the following components:
And that's about it.
Here is a diagram and legend under it
Now, I would bet that you have a vacuum leak at one of the lines either to or from the solenoid valve, which lives under your intake manifold near the throttle body. Check these lines carefully and let me know what you find.