Do you need to replace the O2 sensor on a Honda CRV?
If you do decide to replace an O2 sensor (troubleshoot it first to make sure it needs replacing) use only the proper Denso one. (too many have had problems with the Bosch one in their Hondas). Carbuff2’s suggestions are spot on.
How does the catalytic converter and oxygen sensor work?
If it sees that behavior, it knows the catalytic converter and the oxygen sensors are operating properly. However, if the oxygen sensor doesn’t switch rapidly during the test, the ECM will set a downstream O2 sensor trouble code.
When does an O2 sensor set a trouble code?
If it’s not switching rapidly, the ECM will set an O2 sensor related trouble code If the upstream and downstream oxygens sensors are both switching from rich to lean, that’s the sign of a dead catalytic converter. An exhaust system leak really screws up the P0420 testing routing.
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.
If it sees that behavior, it knows the catalytic converter and the oxygen sensors are operating properly. However, if the oxygen sensor doesn’t switch rapidly during the test, the ECM will set a downstream O2 sensor trouble code.
What happens if you replace the catalytic converter?
If you spend $900 or more to replace the catalytic converter, you may discover the check engine light coming on again later. 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.
If it’s not switching rapidly, the ECM will set an O2 sensor related trouble code If the upstream and downstream oxygens sensors are both switching from rich to lean, that’s the sign of a dead catalytic converter. An exhaust system leak really screws up the P0420 testing routing.
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.