mil/check engine light test failure? smog check experts?

i just got a 98 civic lx 4 dr with 55k miles. i took to for a smog check, it passed comp visual inspection and emissions test but failed the functional check.

it failed on one thing which was the MIL/Check Engine Light. This vehicle failed the MIL/Check engine light test due to the failure to successfully complete all OBD self tests.

i smog checked it wed may 10. he asked me if i unhooked the battery. i said i got it a week ago may 6 and the seller said it died and sat there for 2 weeks until he put a new battery in and sold it to me. he said i had to drive it for about 50 miles on and off. not just on the freeway. he said that it will "program" the ecu or so that the ecu will store it into its memory. is that right? i came back on fri may 12 after 70 miles of on and off driving. he hooked it up to the obd computer and said it still wasn't ready. he showed me on the comuter that the cat and o2 sensor said "not ready" so he said that part of the smog check would certainly fail. does anyone know what's wrong?