alternative way to extract cel/mil codes

hi,

i read my cel/mil codes just a couple weeks ago, (o2 sensor was
replaced). the lite comes on again but now the data link connector
doesnt want to give the codes up, i must have mung it u someway.
i tried to "3m" the light green/yellow wire from #10 on the dlc and
use a coat hanger to engine ground but i still dont get any blinks.

is there another way to extract codes, maybe from the ecu directly?

tia,
peter