Need help getting 1991 back in operation

[dmaclennan]

History:
Original owner, un-modified 1991 with 85k miles - been stored for last 10 years. Trying to get it back on the road.

Issue:
Failing smog test for nitrous oxides [697 ppm vs max 545 ppm at 15 mph. OK, but only just at 25 mph] - CO percentage is twice the max at both speeds and hydrocarbons [103 ppm vs 78 max at 15mph, again just OK at 25 mph]
I sense a very slight occasional surging around 2000+ rpm cycling at around 50 Hz. Don't get anything unusual on the tech 1 using snapshot.

Recent maintenance:
New fuel pumps & filter
New plugs
Repaired vacuum line that was disconnected
New fuel injectors

No codes

Diagnostic Circuit Check with Tech 1
All items in range except:
Blk Learn Enable has value YES and should be NO
Spark advance is 11 degrees and should be 0 degrees

Checked fuel pump operation:
Intial pressure peaks at 58psi and immediately drops to a steady 50 psi and holds. [I assume this means the pump is generating plenty pressure and the regulator valve is also working]
At idle get around 45-46 psi. [I think it's supposed to drop 3-5 psi but not certain]

To do's:
Check spark
Check A.I.R.
Replace O2 sensors - maybe?

Any suggestions? [Other than CA smog test sucks ]

Appreciate any help.

Cheers,
Don MacLennan