1996 Mazda 626 problems caused by driving with bad O2 sensors

Oxygen sensors read the fuel mixture in the exhaust and send the information to the computer. The computer then adjusts the fuel mixture. By not replacing faulty oxygen sensors, you can expect that your check engine light will eventually come on accompanied by erratic idle and poor running. Your car probably will not quit running and there should not be any damage done to it by driving it with faulty oxygen sensors.