If you connect a wire between terminals 10 and GND in the diagnostic box and turn on the key so the battery comes on, the check engine light will come on for a second and then go out. If you dont have any error codes the check engine light will stay off, if you do, it'll flash. Count the number of flashes, short flashes are single digit codes and long ones are for double digits. Ex. 1 long and 6 short = 16 (EGR valve position sensor) I think? 2 long and 4 short= 24. Theres a noticable pause in between codes if you have more than one. Hope that helps. Jai 95 626 couple a mods

i did that and the check engine light just stayed on

Check to see if the wire is connected good. What year Probe do you have? This method doesnt work with 96- because of the OBD-II

ihave a 95 and the wire was connected as good as possible

You might not have any in there. I'll check mine to make sure i told the right procedure and i'll get back to you. Jai - -- In

would my check engine light come on if i didnt have any codes stored? the light comes on after about 10 mins of driving and its usualy when im accelerating