Loud noise at start up

[Dirtyd]

When I start the TB it makes a very loud whining noise, its embarrassing to say the least. I have done some research and found it could be the Secondary Air Injection System. I am not sure if that is whats causing the issue. When I bought the TB it never made that noise, Is this bad? What will get rid of it?

[bdp1978]

If its a loud whine that goes for about 30 seconds during start up....its the air pump. Its located on the frame rail right underneath the drivers door. The loud whine is the precursor to pump failure. Its not really bad, just annoying and will set off a CES eventually. Ive had to replace my pump 3 times, its the single dumbest thing GM put on this vehicle.

Engineers- "Hey, lets hang an electric pump from the frame right where it will get blasted with water and everything else on the road" #2 - "YEAH!! Lets do it, what could possibly go wrong?!"

[The Roadie]

When (not *if*, in many owner's opinion) you get a PCM tune, for instance from pcmforless.com, they can modify the programming to eliminate the error code that will occur if you remove the pump. Then you rip it out and save weight. Its only purpose is to hasten the engine getting into closed-loop emissions mode at a cold startup. An EPA requirement that affected out platform in 2003. 2002 I6 engines did just fine without the system.

[trailburner]

i like the idea of tuning the code out of the pcm and gettin' rid of the air pump system all together. i didn't know it could be done.

sounds better than fixin' a system that's bound to fail again.