What sensor determines the air fuel ratio in the exhaust?
oxygen sensor
An air-fuel ratio meter monitors the air–fuel ratio of an internal combustion engine. Also called air–fuel ratio gauge, air–fuel meter, or air–fuel gauge, it reads the voltage output of an oxygen sensor, sometimes also called AFR sensor or lambda sensor.
How does an air fuel ratio sensor work?
An ordinary O2 sensor produces a voltage signal of 0.8 to 0.9 volts when the air/fuel mixture is rich, then drops to 0.3 volts or less when the air/fuel mixture goes lean. The WRAF sensor signal starts out low and gradually increases its output as the air/fuel ratio gets progressively leaner.
Does octane affect air-fuel ratio?
What does octane do? It just prevents the air-fuel mixture from igniting before the spark plug does it. Firing the air-fuel mixture at the proper time gives you the maximum power your engine was designed to get. Using higher-octane gasoline than your engine is designed to utilize is only wasting your money.
What are the symptoms of a bad air fuel ratio sensor?
1. Decrease in fuel efficiency One of the first symptoms of a problem with an air-fuel ratio sensor is a decrease in fuel efficiency. The air-fuel ratio sensor monitors the oxygen content in the exhaust stream and sends data to the computer so that it can add or subtract fuel.
What causes an oxygen sensor to read too lean?
As the pulse passes, the low-pressure can suck in gases outside the manifold. To your ears, it may sound like a pop or a puff. To the oxygen sensor, the change to the exhaust gases in the manifold can cause inaccurate readings. The escaping gases and the outside gases cause the sensor to read too lean.
How can I test my air fuel sensor?
The most accurate way to test A/F sensors is with a factory scan tool that displays the PCM’s actual voltage reading for the A/F sensor, or an aftermarket scan tool that can do the same. The coat of soot on this unheated oxygen sensor reduces its sensitivity to changes in the air/fuel mixture ratio.
What causes a crack in the exhaust manifold?
The engine management system does not know there is a crack in the manifold. When the exhaust valves open, the exhaust gases are pushed out into the exhaust manifold by the upward movement of the piston. The escaping gases form a pulse in the exhaust manifold.