What im asking is are you just messing with it?
You have no check engine light while normal driving right?
Its fine since it is obd1 it will stay solid unless something is wrong.
You dont turn the car completely on when checking only to the on position
well my air fuel guage was not working corectly (yeah i know they are not accurate) but never had no problems with it. so was just cheching the code to see if anything came up.
well i have a monitor (vafc) that block the view of the check engine light. but the vafc cannot make adjustments it was sort of unwired that way when i was getting a base tune done and was that way when got it fully tuned so don't think that wouls cause any issues.
ok so when testing the check engine light will stay solid until a problem comes up. but in obd0 where you check he light on the ecu itself if it stays solid that means the ecu is bad.