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Old 11-12-2001, 01:06 PM
Arthur Dalton Arthur Dalton is offline
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Join Date: Aug 1999
Location: Florida / N.H.
Posts: 8,768
If you do disconnect the AIR pump, a couple of things to know.

There is a switch-over valve that should also be disconnected. This valve is wired in parallel with the feed wiring to the pump clutch. So, when the pump is energized, so is the sw/over valve.
[ the purpose of the s.o.v. is to allow opening vacuum to the air check valve between the pump and the exhaust . Otherwise, the pump
can not pass the air to the exhaust]
If this is not done , this check valve is opened when the ECU calls for AIR. [ no good]
But if you disconnect it electrically, you will bring up a sov code.
So a BB in the vac line between the sov and pump check valve solves that one. [ leaving the sov plugged in to fool the diagnostics module].
But , unplugging the AIR clutch magnet to disable the pump also throws a code.
Takes a while to pop, but it will. On your car with the led/sw combo, this is easy to erase when needed. But i think [ have not tried this yet], a small lamp for circuit completion at disconnected pump feed will do that one.
If the noise is only coming from a pump when energized, disconnecting will work, but if a pump is noisy even in the off mode, it has bad pully bearings and has to be replaced.
As far as cat damage and EPA, I really don't think the 20/30 seconds that this pump is called for makes a big difference. These cars with Heater style 02 sensors go into closed loop
quickly, and the pump is never called for in closed loop.
My own opionion is cat damage is more probable with egr disconnect than AIR. [ On you model, anyway]
I also think that a lot of pump failures may be that the sov/ck. valve are at fault and possibly damaged the pumps by not closing down when needed [ ie. - closed loop]
Not advocating disconnecting anything, just pointing out some of the particulars of the systems operation, as I know it.
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