Speaking of the battery cables, is there any chance a voltage drop across the positive cables could cause the ECM memory to be erased . . . which would continually reset the monitors and never allow them to set?

Also, shouldn't this throw a code?

Hey, everyone. I'm pulling my hair out trying to get my 1999 S70 to pass the California smog test. Emissions aren't the problem. It's the stinking computer. Several months ago I disconnected the battery to clean the posts, and when I did that it reset all the computer monitors. 1500 miles later, thr...