I resently bought a 1996 accord, its registered out of state, and I'm in california, so I need to get a smog for it to be registered. I took it to a smog guy and be told me that it wont pass because it has 3 monitors that are not ready (I dont know the codes but he said its the EVAC, o2, and cat converter monitors). He also explaned that the previous owner most likley cleared a check engine light before it was sold to me. They said I need to drive around for a while and the monitors will clear. After 90 miles, there was no change in the monitors, still had 3 not ready. They also said the the EVAC sensor is independant, but the cat converter sensor wont reset unless the o2 clears and is working properly, like they are linked. The smog guy said I should get a new obd 2 sensor (upstream) and have him put it in, then drive around for a while again and see if some of the monitors reset and become ready for the smog. He said it should have reset by now so something is wrong. I also called a honda specialist and told him the situation, he said sometimes it takes weeks to reset the monitors depending on your driving habbits, he recommended that I keep driving it, not replace the sensor. And also, if the obd2 sensor isnt working properly, then the privious owner may not have reset a check engine light, right? Because if monitors wont clear, the check engine light wont come on in the first place, right? Any information on this subject would be greatly appreciated, I'm on a budget and this is turning into a headache, I got conflicting information from the 2 different guys I spoke to.