1996 850 2.4l non-turbo, 92,718 miles.

I found a broken vacuum line (from intake manifold to SAS vacuum switch),
fixed it, re-test and still failed the NO test at 15 mph. I would really
appreciate any suggestion to get it to work.

15mph %CO2 15, %O2 0.0, HC PPM 3, CO % 0.06, NO PPM 591 (failed)
25mph %CO 14.9, %O2 0.0, HC PPM 1, CO % 0.10, NO PPM 558

It has new spark plugs, cap, rotor, & air filter about 5,000 miles ago.
I removed all spark plugs, cleaned them and re-adjusted the gaps before
the re-test. There is no OBD II fault code after I fixed the broken
vacuum line and erased it (one code said mixture too rich).

I removed SAS valve and it seemed to be shut all the time. The air pump
inlet side is clean, and I cannot blow air through it at all. But, the air
can blow from the bottom through vacuum inlet. Carb cleaner can flow thru
the bottom to vacuum inlet, too.

After I put everything back, once I skipped the vacuum switch (or pump?)
on top of radiator fan and jumped the SAS valve vacuum line to the check
valve, the engine run with a pup-pup-pup sound but smell better (by
my nose). It seems to have an air pump noise then, and was quiet before
I jumped the vacuum lines across the switch.

I have some questions:
1. Is there some thing else causes this high NO (or NOX) result?
2. How to test the air pump, and where is the air pump relay?
3. Is it a vacuum switch, or relay, or pump above the radiator fan?
4. How to test the SAS valve exactly?