Why does my downstream O2 sensor show Bad readings?
The downstream o2 sensor’s job is to monitor the catalytic converter. Most mechanics will often say it’s the o2 that is shot when it is actually the cat. When the cat is restricted, the downstream o2 will show bad readings. Understanding downstream and upstream, LTFT (long term fuel trim and STFT…
What does the downstream O2 sensor do in a catalytic converter?
The downstream o2 sensor’s job is to monitor the catalytic converter. Most mechanics will often say it’s the o2 that is shot when it is actually the cat. When the cat is restricted, the downstream o2 will show bad readings.
What causes a low O2 sensor voltage signal?
Excess oxygen in the form of regular ambient air will send the O2 sensor voltage signal low (under 0.450 volts) and lack of it will send the voltage signal high (over 0.450 volts). A stuck open EGR valve will create a lack of oxygen in the exhaust, since the re-circulating exhaust has all its oxygen already burnt.
How does the O2 sensor in a car work?
The O2 sensor in your vehicle monitors the exhaust gases coming out of the engine. It determines the amount of oxygen in the gases, which indicates how well the fuel is being burned. The O2 sensor then sends information to the electronic control unit, or ECU, the vehicle’s computer.
The downstream o2 sensor’s job is to monitor the catalytic converter. Most mechanics will often say it’s the o2 that is shot when it is actually the cat. When the cat is restricted, the downstream o2 will show bad readings. Understanding downstream and upstream, LTFT (long term fuel trim and STFT…
The O2 sensor in your vehicle monitors the exhaust gases coming out of the engine. It determines the amount of oxygen in the gases, which indicates how well the fuel is being burned. The O2 sensor then sends information to the electronic control unit, or ECU, the vehicle’s computer.
The downstream o2 sensor’s job is to monitor the catalytic converter. Most mechanics will often say it’s the o2 that is shot when it is actually the cat. When the cat is restricted, the downstream o2 will show bad readings.
How to diagnose O2 sensor heater circuit failure?
The modified test harness with the light will give you easy access to the circuit. Remember, the engine needs to be running at this point. If the voltage is close to zero on the positive heater wire, then locate the open circuit in the power wire back to the fuse. Again, it may have a relay in the circuit as well.