Got Error Code P0430, What To Do?
First off, how many miles are on your car? If it turns out to be a cat, they have a mandatory warranty of 80k miles and I forget how many years...
Chances are, however, though, that it is just an o2 sensor, if it is stuck at a certain voltage, it should be .4-.5 volts if the cat is functioning properly and being low, would show that the cat is bad, or, the o2 sensor just isn't reading properly... swapping with a known good one (perhaps from the other bank if the connectors fit) - if the code follows the sensor side, then its the sensor, but if the code stays on the same side, its the cat...
If it does end up being a catalytic converter, it is just an efficiency issue - if under warranty, have Lexus replace it free, if not, you can just leave it alone and ignore the light, so long as you don't live where they do emissions testing... replacing with headers would not fix your check engine light, as they would eliminate the cats completely, leaving you in no better shape than you are now
But basically my CEL is intermittent and comes on at random times and off. I asked a Lexus tech about the code and he plugged in the Techstream program and ran some Health Check and Bank 2 Sensor 2 kept reading 0.2 to 0.3 while the other one was 0.2 to 0.8 at different RPM.
And thanks for the suggestion. One of the two O2 sensors is working properly so I'll switch them around since they are the same and I guess if an error relating to Bank 1 shows up, then it's the O2 sensor that is bad then.








