1996 Nissan Sentra disappearing oil
The car has never used oil and i took it to the Nissan shop and they replaced the valve cover gasket. When i drove off the car hesitated with some smoke so i drove to work 87 miles and back home and the car was 2 quarts low in oil. I put oil in drove to work and oil was 1 quart low. Took car to Nissan shop they can't find any oil leak check everything. Nissan said to replace valve cover. But they don't know if this will fix it. The car has never used oil and i change the oil every month.

Any suggestion

If you're not leaking, than you're burning it during the combustion process.

Check the spark plugs for oil coating