Kwiksen 2pcs Oxygen Sensor Upstream &Downstream Sensor 1 Sensor 2 for 2001-2004 Pontiac Grand Am 3.4L,for 2001-2003 Chevrolet Malibu Base 3.1L,for 2003-2004 Oldsmobile Alero GL 3.4L 2x Front & rear O2 oxygen sensor 1 sensor 2 for 2003-2004 Oldsmobile Alero V6-3.4L O2 Oxygen sensor upper & under for 2001-2004 Pontiac Grand Am 3.4L 2x Upstream & downstream O2 oxygen sensor for 2001-2003 Chevrolet Malibu 3.1L Upstream sensor length 400 mm ( 15.75 inch), downstream sensor length 1200 mm ( 47.24 inch). Wires: 4 Warranty: One year unlimited miles.Please check compatibility chart before buying.