Why do catalytic converters have oxygen sensors?
Oxygen Sensors, commonly referred to as O2 sensors, are part of your vehicles emission system. The purpose of the downstream, after converter, sensors is to monitor the quantities of harmful exhaust gases flowing into and out of the catalytic converter to ensure the converter is working properly.
What does the sensor on the catalytic converter do?
The downstream oxygen sensor, on the other hand, should show very little movement. It’s testing the catalytic converter to see if it’s storing oxygen during rich events and then using the oxygen during lean events.
Can a bad catalytic converter cause an oxygen sensor to go bad?
In 99.5% of the cases, this code means that the catalytic converter itself is bad and must be replaced. However, I see questions all the time on auto forums asking if a new oxygen sensor will fix the problem.
Why is my catalytic converter reading lean 0.1v?
An exhaust system leak really screws up the P0420 testing routing. An exhaust leak near the upstream sensor can cause the downstream sensor to read a steady lean condition. The ECM would interpret that as a bad catalytic converter. In that case, your OBDII scanner should be reading a lean 0.1v reading from the downstream sensor.
Do you have to replace the catalytic converter?
If they replace the catalytic converter, they are going to insist on replacing the oxygen sensors as well or they won’t stand behind their work.
What is a bad O2 sensor?
Bad O2 sensors are one of those car problems that most drivers tend to postpone until more serious problems occur. These symptoms will rarely cause any immediate damage, but over time, if left unattended, they can cause damage to the engine and other systems mainly through improper air-fuel mixture.
What does a catalytic converter OBD II mean?
What does a Catalytic Converter OBD II mean? OBDII (On Board Diagnostics II) systems are required by Federal law on all passenger cars and light trucks manufactured since 1996. It is a computer on board the vehicle that monitors the engine and emission control equipment to verify that all systems are working properly.
What is a good oxygen sensor reading?
The primary O2 sensor reading should range between 300-600mV sometimes going as low as 100 mV and as high as 900 mV and the reading will change quickly.
What is a catalytic convertor?
A catalytic converter is an exhaust emission control device that reduces toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction (an oxidation and a reduction reaction). Catalytic converters are usually used with internal combustion…