Do you need an oxygen sensor for a catalytic converter?
Most modern catalytic converters are equipped with one or more oxygen sensors that monitor the efficiency of the car’s exhaust system continuously. If your catalytic converter has an attached oxygen sensor, use an oxygen sensor socket and a ratchet wrench to disconnect it before proceeding.
What should I do before replacing the catalytic converter?
Some mechanics will tell you to try replacing the oxygen sensors first, to see if that solves the problem. There are two of them, one before and one after the catalytic converter.
How are catalytic converters secured to the exhaust system?
Typically, catalytic converters are secured in two ways: either bolted up at the flanges or welded directly into the pipes of the exhaust system.
How do you remove an oxygen sensor from a car?
If your vehicle has an oxygen sensor mounted in the catalytic converter, pull the wiring harness off of the sensor before removing the catalytic converter. Once the converter is removed, place an adjustable wrench on the sensor and twist it out of the converter in a counter counterclockwise direction.
Most modern catalytic converters are equipped with one or more oxygen sensors that monitor the efficiency of the car’s exhaust system continuously. If your catalytic converter has an attached oxygen sensor, use an oxygen sensor socket and a ratchet wrench to disconnect it before proceeding.
Some mechanics will tell you to try replacing the oxygen sensors first, to see if that solves the problem. There are two of them, one before and one after the catalytic converter.
When do I need to replace the oxygen sensor?
If the sensor after the catalytic converter shows minimal changes from the reading on the first oxygen sensor, it is a sign that the catalytic converter is not working properly. Modern vehicles with V-6 or V-8 engines could have as many as four O2 sensors — one located in each cylinder bank and one after each catalytic converter.
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.