Hi. Recently bought a 55k mile rx8. Shortly after purchase, had squealing from under the hood, until car warmed up. Squealing eventually stopped during subsequent startups, but CEL for secondary air injection appeared.
Thought possibly air pump , so disconnected the air pump hose and found no air flow while car was running. Pump's air outlet smells kinda burnt. Thinking it may be bad, but a couple questions before buying a new one:
Is the air pump "always on", and the solenoid controls the flow to the exhaust? Or is there a relay that will periodically turn on the pump? Can't really tell from the service docs.

Thanks.

airpump only runs for a short time when starting up cold. It's to push extra air into the cat. useful only for emissions.

many people remove it completely.

Thanks, that makes sense. I had a friend start the car while I monitored the pump outlet. Didn't detect any airflow. Car wasn't super cold... but had cooled for about an hour since driving (if that matters).

test it after the car has sat overnight.

if you find out that yours is broken and you need to replace it, PM me. I recently removed mine.

Cool... if it is the problem, that'll work out swell. I need to have no CEL and all OE parts for the stock class Autocrossing.

Well, no air flow from from pump at startup (30 deg outside temp). There was an audible exhaust note from the air control valve for a few seconds, with the rubber air hose disconnected. So seems like the control valve was open and "expecting" some air from the pump at that point.