The Oxygen sensor keeps an eye on what's future elsewhere of your engine so it knows what to levy in.
The principles automotive personal computer uses large sensors that detail as the authority manner's eyes and ears in your engine. The Bulk airflow and manifold air vigour sensors bid the machine how still air is going in, and the Oxygen sensor tells it what happens after that air combines with fuel in the cylinders. While the pc may go on to operate without info from the Oxygen sensor, you mess with this constitutive Element at your threat.
O2 Sensor Basics
An O2 sensor is essentially equitable a appropriate sturdy, express specialized thermometer that hangs down inside your exhaust stream. Exhaust temperature rises or drops relative to the dimensions of fuel in the exhaust stream. The thermoelectric information in the Oxygen sensor produces electricity when it gets calescent; the hotter the facts, the higher the voltage. The personal computer reads that voltage and extrapolates from the the engine's ongoing air/fuel ratio. On a petrol engine, pre-converter temperatures Testament rise as the air/fuel ratio gets leaner, and post-converter temperatures Testament Blop. Speaking of the converter: the moment Oxygen sensor monitors your catalytic converter, and rendering it inoperable Testament pitch your personal computer into "limp-home" income until you shop for it constant.
Heated O2 Sensors
The hot water with the thermoelectric facts in the Oxygen sensor is that it onliest produces voltage above a certain temperature (about 600 degrees), and it takes time to receive the sensor up to that temperature. Until the O2 sensor gets up to temperature, the engine operates in "open-loop" mode where it uses its best guess to determine air/fuel ratio.The average oxygen sensor will have one to four wires. The single wire on a one-wire O2 sensor is the sensor's positive output wire; in this case, the sensor is grounded to the exhaust pipe. The wires in two-wire sensors will typically consist of the positive sensor wire and the heater power supply wire (the sensor is still grounded to the pipe) or the sensor output positive wire and a ground wire for the sensor.
Heated O2 sensors use an electrical heating element to receive the sensor up to temperature more quickly. Without a heating element, your car would stay in open-loop mode long after start-up or after long periods of idling.
O2 Sensor Wiring
Three-wire configurations will use a positive sensor output wire, a positive heater power-supply wire and a ground wire that services the sensor, the heater or both. If you have a four-wire sensor, then the sensor and heater use separate grounds.Disconnecting the Ground
What happens when you disconnect a ground wire depends on the sensor. Disconnect the ground on a two-wire sensor and you render the sensor inoperative. Disconnect it on a three-wire sensor and you may render the sensor, the heater or both inoperative. Cutting either of the ground wires on a four-wire sensor will kill either the sensor output or the heater function, depending on which ground you cut. Killing the heater will simply keep your car in start-up mode (open-loop mode) longer after you start it or when you've been idling, causing a reduction in power and fuel economy. Slicing the sensor's ground wire will throw the computer into open-loop mode permanently.
