I just got my '84 back from the paint shop (after almost 2 years) and the check engine light is on all the time. I bought an old style GM code reader and it's not throwing any codes, not even the "12" code which I guess means the system is working. I replaced the PCB last year and all the lights and gauges work so I don't thing that's the problem and it runs great, just like before. I thought it might be a bad code reader so I jumped the 2 correct pins with a paper clip and still nothing. Any ideas?