What is a air fuel sensor heater circuit?
The air/fuel ratio sensor heater element is controlled by the ECM based on signals coming from engine coolant temp and engine load. Voltage signals received through the heater element circuit are monitored by the ECM, which determines the state of the circuit by comparing voltage with factory specifications.
What is the difference between air fuel sensor and oxygen sensor?
An air/fuel sensor can read a much wider and leaner range of fuel mixtures than a conventional O2 sensor. That’s why they’re also called “wideband” O2 sensors. Another difference is that A/F sensors don’t produce a voltage signal that suddenly changes on either side of Lambda when the air/fuel goes rich or lean.
What is a rich AFR?
Lean or Rich Mixtures When an air/fuel mixture has too much fuel, it is rich. An AFR higher than stoich = lean. An AFR lower than stoich = rich. A lambda value higher than 1 = lean. A Lambda value lower than 1 = rich.
What can a bad MAF sensor do to a Toyota 4Runner?
The mass airflow sensor (commonly abbreviated to MAF) is one of the most important engine management sensors. A bad mass airflow sensor can leave your Toyota 4Runner’s engine running rough, or even inoperable. A MAF sensor measures the density of the air entering the intake manifold.
How does the air fuel ratio sensor work?
The faster the air-fuel ratio sensor reaches that temperature the faster the sensor will start sending an accurate signal to the Engine Control Module ( ECM ). In order to achieve the require temperature, a heater element is included inside the air-fuel ratio sensor.
Why does my Toyota 4Runner jerk on the road?
Jerking – As you go down the road, you’ll feel your 4Runner really jerk and hesitate as the engine speed changes erratically. It’s bad for your motor mounts when this happens. Also, jerking can be caused by bad spark plugs or coil packs.