What would make a check engine light go on in a 1998 Honda Accord EX 98?

From my experience, its usually the bank 1 oxygen sensor. Lemme guess it sometimes goes off. But, always come back. Some strange reason the most expensive oxygen sensor goes out on the 98 Accords. Just to be sure find someone with a OBDIII reader, just to make sure. If it's a 4 cyl it could be the gas cap being loose.The convertor being worn (if it is and under 80k bring it to a dealer it will be for free)It could the fuel pressure regulor.But the most common is the canistor vent shut valve. If it is a V6 gas cap loose, canistor vent shut valve inop. or the convetor or the EGR tubing is clogged. If it's the EGR bring ti to the shop the intake maniflod must be removed and drilled and egr valve be replaced. Plus 8 yrs 80K miles all emission stuff is free. I have never seen a 98 Accord with a bad O2 sensor. Our Check engine lightm came on. We took it to "Auto Zone" parts shop. Their 'machine' said it was an O2 sensor. But when we took it to a car dealer, their 'machine' said it was the Cadalitic Converter. 2 weeks ago the light went off and hasn't come back on.