Check engine light on and code P0430

Hello, I'm Danny.

That particular code is for catalytic converter deficiency. Here are a few tutorials to view about catalytic converters:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

https://www.2carpros.com/articles/catalytic-converter-replacement

I've attached picture diagnostics steps below for your vehicle. Hope this helps and thanks for using 2CarPros.

Hello again Danny, I did some intense diagnosis and have more information for you. I used my scanner to see live data and noticed that bank 2 sensor 2 which is after the catalytic converter by the engine was fluctuating the voltage quite a bit. And once in a while it would go to 0.0 volts when I let go of the accelerator pedal. As you have said, I don’t see any symptoms of a failing catalytic converter because even when the check engine light is on the car still has full power and don’t feel a loss of power. Bank 2 sensor 1 doesn’t fluctuate a lot and is steady. I have attached 2 videos of showing the operation of the sensor and you can see sensor 2 showing 0.000 volts when I was cruising at 45 MPH.

Hello, I did some intense diagnosis and have more information for you. Every time I go on a small road trip more than 50 miles, my check engine light would come on. I used my scanner to see live data and noticed that bank 2 sensor 2 which is after the catalytic converter by the engine was fluctuating the voltage quite a bit. And once in a while it would go to 0.0 volts when I let go of the accelerator pedal. As you have said, I don t see any symptoms of a failing catalytic converter because even when the check engine light is on the car still has full power and don t feel a loss of power. Bank 2 sensor 1 doesn t fluctuate a lot and is steady. I have attached 2 videos of showing the operation of the sensor and you can see sensor 2 showing 0.000 volts when I was cruising at 45 MPH.

A failing catalytic converter won't show any real drivability issues but your description and voltages say there is a problem with either the wiring or the B2S2 sensor. 0 volts sounds more like a short or breaking wire that is dropping the voltage, I would get the vehicle up so you can go under it and check the sensor, it's connections and wiring. If the wiring is bad in some way the P0430 code could be from that.

Hello Steve thanks for the reply, I looked at the wiring and it seems okay. I’m assuming the sensor itself is bad because all of them are original to the car with more 210,000 miles on it. I actually scanned the car today and took a picture of the code. The scanner is telling me that bank 2 sensor 1 is bad even though it was performing as it should. B2S2 is the heated one right?

Both of the upstream sensors are lambda type air fuel ratio sensors and both downstream units are conventional heated O2 sensors. The downstream units shouldn't bounce around a lot if they are working and if the cats are working correctly.
The P0430 code will be set if the voltage from the downstream sensor is changing a lot once the engine is warmed up. Very possible the sensor is bad with those readings.

Thanks for the information. I am going to replace that sensor and see if that will help.when I went to the parts store today they asked me which sensor I was looking for downstream sensor left or right. This car only has 4 sensors and the one that is faulty is the one next to the radiator after the cat. Can you tell me the correct part number for denso?

They asked because Toyota used 4 different part numbers even though there likely is no difference other than wire colors or length. The Bank 2 Sensor 2 is the one in circled in blue.
That is Toyota part # 8946548170 Denso #2344168

Thanks for your help.

You're welcome. Please let us know what happens.

Hello again Steve, so I did replace my 02 sensor and looked at the live data and it’s showing 0 volts only when i'm braking. Just like before it won’t show check engine light until I go on a short trip. Is this normal? I heard of a TSB that Toyota had where they updated the software on the computer and installed a new style catalytic converters. Will I still be able to get that update?

Can you graph the rear O2 sensor? I attached some waveforms for you showing a bad catalytic converter. If the voltage on the rear sensor does not stay steady, the catalytic converter is bad.

Roy

Hello again.

Have you had the catalytic converters tested? This is the code source- not the heated oxygen sensors but catalytic converter deficiency. Do you have access to an infrared gun? If you do then test the input and output temperatures of the catalytic converters and it can tell you their performance. If the catalytic converters are working properly you will notice a plus or minus 400 degree additional heat temperature compared to the inlet temperature due to the emission process with the converter. Hope this helps and thanks again for using 2CarPros.

Danny-