2003 Gen 1 ICE runs rough, shakes, stalls and throws up all lights

Lots of similar posts but none of the typical solutions I have read on these forums seem to help me. So far I think I've ruled out:

MAF - I have cleaned it
Throttle body - I have cleaned it and it is not stuck
Fuel - tank is full
Oil - level is just below the top dipstick mark
12V battery - has been replaced as is fully charged

Had trouble with OBD II reader as it just seems to shut off rather than read codes. Once though, I got it to work and it told me there were no DTC codes!?

I have an appointment booked with the dealership in order to read codes/diagnose, but I have very little faith that anything positive will come out of it. Any comments or suggestions are appreciated.

 

*** also please advise if this should be posted in a different forum ***