What are the functions of the downstream sensors?
The role of the downstream sensors is to monitor the output and health of the catalytic converter. Removing them will take away this function, and produce a CEL (check engine light) or MIL (malfunction indicator light) on the vehicle. I am getting a CEL/MIL and a . . . code.
What does the downstream zirconia sensor voltage indicate?
In brief, the downstream zirconia sensor voltage hovers around 0.7 volts, indicating to the ECM that the catalytic converter is performing to specification. In addition, downstream sensors can provide a default value when an upstream sensor fails.
Why do you need an upstream O2 sensor?
Upstream O2 sensors are part of the engine’s fuel feedback control loop, and are necessary to maintain good fuel economy and low emissions. A conventional upstream O2 sensor is essentially a rich/lean indicator that the powertrain control module (PCM) uses to balance the air/fuel ratio.
Why does my car have a low voltage sensor?
This error code is triggered by your car’s primary computer—often referred to as the powertrain control module (PCM)—when it perceives a problem with the oxygen (O2) sensor. More specifically, this means that the PCM is detecting a low voltage from the #2 O2 sensor in Bank 1.
Upstream O2 sensors are part of the engine’s fuel feedback control loop, and are necessary to maintain good fuel economy and low emissions. A conventional upstream O2 sensor is essentially a rich/lean indicator that the powertrain control module (PCM) uses to balance the air/fuel ratio.
What should voltage be on zirconia upstream oxygen sensor?
A traditional zirconia upstream oxygen sensor produces a voltage signal that continuously switches back and forth. The reading gives the PCM an idea of the engine’s air/fuel mixture. A value above 0.45 volts indicates a rich condition, while a reading below 0.45 volts indicates a lean condition.
What does high voltage mean on O2 sensor?
The high voltage condition from the O2 sensor is indicating a lack of oxygen in the exhaust or other related problems, such as a leaking fuel injector or a broken up catalyst inside. Need help with a P0138 code?
What does the downstream O2 sensor do in a catalytic converter?
The downstream O2 sensor controls the heat of the catalytic converter. It slightly richens the mixture to make the cat heat up faster, and it leans it a bit if the cat gets too hot. Basically it keeps the cat in the optimum temp range to work right. It is true that it could damage the cat by making it get too hot if it’s not sensing correctly.