I'm struggling to find the proper definitions, bins, etc for this S10 truck I bought.
4.3L V6 TBI, with E-Trans (4L60E), VIN designates as a "Z" (not a turbo like some lists indicate)
I'm thinking it could be the 427 PCM but don't know for sure.

It has 157K with a two yr old cat con on it, but runs really good.
Its failing emmissions for high (super high) NOx.
HC = 4.8 reading, 151.0 limit
CO = 0.0 reading, 1.68 limit
NO = 2788.9 reading, 956 limit (FAIL)

Ran it for an hour on highway and went back...
HC = 4.5
CO = 0.0
NO = 1822 reading (FAIL)

I'm figuring its the EGR solenoid since the valve opens and closes with vacuum applied.
I'd like to get in and turn on the solenoid to confirm the PCM is controlling it.

All info I find drops off the radar at 1993.
I know 94 is a bad transitional year so I could be in for a fun time.
Its OBD1 connector but gets nothing but jibberish using the $0D definitions so I'm wondering if there is a different one I should try.

Basically fishing for ideas..
Possible BCC and PCM numbers, ($E6 leftover?)
TIA,
Jp