You want a wideband sensor, nothing else. Not a 1,2,3 or 4 wire sensor but a Bosch LSU4 sensor. Think it has a 6 wire connector. The sensor is cheap at around 40£ max, but it need a driver and a display. Around 200£ total at very cheapest. All other type sensors are only good at tuning a engine optimally for a catalysator.