my is going out i think its making a high squeal sound just wondered what it did btw I have a 94 3.4 5spd

 

Pumps air

 

It pumps air into the exhaust manifold to burn up pollution.

If it went out, i would guess that it might damage the cat and would be sure that, if you had to take emissions tests, you would fail.

 

...here the OFFICIAL explanation per the regulations of the Peoples Republic Of Kalifornia

The air pumps works at cold engine temps, to help add extra air upstream (before the cat), to help burn remaining HC (unburnt fuel), in the exhaust system to help quicken CAT warm-up time, also do the richer air/fuel mixture at cold engine operation until the O2's warm up.

After warm-up (the O2's are in control of fuel delivery and are at approx. 650degrees). the diverter valve will switch the air downstream (after the cat)..........to continue help burn the excess unburnt fuel.....however I don't think the 3.4 v6 setup does it part of it.

In other words.........to help warm the cat and the O2's.

There's you smog test info. for the day