Early EDM non-cat 4A-GE 16v Bluetop Fails emissions (high co)

[Rascal21]

I`m at a bit of a loss here.
As the topic states my Early EDM non-cat 4A-GE Bigport Bluetop engine fails on emissions test, should be 1,5% CO.
During the first inspection a couple of months ago it read 6,7% at idle when warm..
During the second inspection attempt a week or so ago it read 6,8-7,2% at idle when warm.
Today it read 8,2% at idle when warm.

During and/or between the last two attempts I`ve been fiddling with the CO potmeter but can only shave 0,3% of the reading (8,2% goes down to 7,9%).
Been trying my hand 3 times at the inspection, at one point even briefly swapped for a different CO potmeter, but same thing, can only shave 0,3% of the 8,2% reading.

The TPS was a bit off position (slightly anti clockwise to where it should be sitting) and as a result I had rev hunt when slowly throttling up to 2500rpm when it`s not in gear, adjusted TPS back to where it`s supposed to be sitting (it was marked) and now no longer have that problem (Have not put it through inspection after this change)-

Runs very rich (Lambda value is 0.800, should be above 1.000, or if thats 800 and 1000, donno anymore, exhaust fumes been killing me), adjusted idle between 1200 rpm and 750 rpm just to see what would happen.

No exhaust leaks, exhaust is pretty new, new muffler etc.

Tried a oil change, spark plug change, checked compression, dizzy cap, rotor, plug leads both when slacked and when pulled etc, also I swapped ECU and igniter+coil+cap+rotor+leads, plugs etc, no difference in behavior.
Coil+ign has good earth, battery is nice and healthy changed it for the lels but no difference, alt charges nicely, again changed it thinking maybe injectors were getting low voltage, again no dice.
Fresh fuel as well, no fuel leaks, no oil leaks, oil pressure good.
You know, all the usual stuff.
No error codes i.e no bad sensors, also manually checked them by pulling the connectors (pull TPS = Engine stops) and so on, also checked them according to FSM (measure resistance/voltage across pins etc) again, the usual stuff, no dice.
Plugs are nice too of course, also installed some black ones on purpose and as expected got unstable idling.

For just driving the thing is great, 4th and 5th gear up inclines at 2000 rpm using 3.9 CWP without breaking a sweat what so ever.
Pulls hard and healthy all the way up to 7500rpm rev-limit, no odd behavior, no noticeable power loss etc, and considering how rich its running I actually get rather nice mileage (compared to the 2T that the 4AGE replaced in the first place)

I`ve had my fair share of tough ones and have accumulated a bit of experience due to that (as you may notice by everything I`ve crossed off the list), but this one is over my head even with what little I do know.
Would really appreciate any suggestions that I havent yet checked/tested/tried out yet, I`m not proclaiming to be the best or anything, just need the daily grocery getter/parts getter to pass inspections so I can keep using it for it`s intended purpose