Original BOSCH Lambda / Oxygen / O2 Sensor

Front ( pre-CAT )  ( up stream )   - replaces the part numbers below    

HYUNDAI    3921022100

BOSCH      0258003957  Supersedes: 0258003006, 0258003009, 0258003014, 0258003019, 0258003028, 0258003032, 0258003040, 0258003061, 0258003075, 0258003090, 0258003101, 0258003175, 0258003206, 0258003234, 0258003298, 0258003931, 0258003994