P219B Diagnosing

P219B code came on back in October of 2023. Light would go off when randomly and stay off for months. It would repeat this every couple months but it has been off for probably 8 months now. Now it is back and showing up as a permanent code. Spark plugs were changed back in September so they shouldn’t be the issue. I ran some live data that I will upload photos of. I’m not too sure how to interpret the data. Today I got under the truck and tested the back O2 sensor on both sides with a multimeter and got 14 ohms of resistance and 0 volts while the car was running. Didn’t have time to check the higher up O2 sensors. Do I need to replace the O2 sensors? Also if they aren’t the problem what should I do next? I also cleaned the MAF sensor and throttle body this morning.

 

Can’t post the video but here’s a summary of the live data:
O2B1S2 and O2B2S2 are both showing around .8 Volts pretty much constantly
O2B1S1 and O2B2S1 are both alternating between about 3.2 and 3.3 Volts.
Not sure what to make of this

 

Take a look at the code data chart in the pdf below.

 

Dang, I didn't realize our systems monitored to this level.
I think I'd be checking bank 2 injectors?

 

It’s not a video but here’s what the live data screen looks like. I’m going to try the diagnosing procedure in the pdf you sent. I’ll update on how it goes.

 

The upstream sensors are AFR (Wideband) sensors, they operate differently from standard (Narrowband) O2 sensors. They actually operate based on current but the value is displayed as a voltage.
14.7:1 AFR = about 3.3v on Toyota

DESCRIPTION:
The A/F sensor generates a voltage* that corresponds to the actual air-fuel ratio. This sensor voltage is used to provide the ECM with feedback so that it can control the air-fuel ratio. The ECM determines the deviation from the stoichiometric air-fuel ratio level, and regulates the fuel injection time. If the A/F sensor malfunctions, the ECM is unable to control the air-fuel ratio accurately. The A/F sensor is the planar type and is integrated with the heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), a current flows into the heater to heat the sensor, in order to facilitate accurate oxygen concentration detection. In addition, the sensor and heater portions are narrower than the conventional type. The heat generated by the heater is conducted to the solid electrolyte though the alumina, therefore the sensor activation is accelerated. In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric level. * : Value changes inside the ECM. Since the A/F sensor is the current output element, a current is converted in to a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors will show a constant voltage.

It started around 2012, they can monitor air/fuel ratio differences between banks. 2015+ can monitor it per cylinder.