Since carbon monoxide is produced from the incomplete burning of natural gas or other carbon-based fuels, wood, coal, and oil, electrical kitchen appliances, including ovens that don't require these fuels to work, do not produce CO. However, if the electrical oven starts a fire for one reason or another, then the fire itself will produce some level of carbon monoxide. But unlike the gas appliances that can emit this poisoned, colorless, odorless gas without you noticing, you would certainly detect the fire by flames and smoke.