Can faulty Passlock chip is car key cause check engine light to come on?

Pontiac Sunfire 2000. Check engine light (CEL) came on. Garage ran scan, replaced cylinders, CEL off. I drove 2 days but only a short time and distance each trip. CEL came back on when my husband drove. Garage said drive for over 30 minutes and drive for a week, hopefully the module will reset. But CEL stayed on. Garage checked module. It is okay but said it was the O2 sensor. They reset the module. CEL went off. I drove a few days then my husband drove. The CEL came back on! (This could really cause marital strife!) The only difference is he uses his key, I use mine. Can the key chip/passlock be causing the problem. What do I do next?