Odd Issue with Fuel Trims

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    Hi Everyone. New guy here. I have an issue with my 2005 Toyota Tacoma v6. 195k miles. I currently have two check engine lights, P0138 for O2 Sensor Circuit High Voltage Bank 1 Sensor 2 and P0157 for O2 Sensor Circuit Low Voltage Bank 2 Sensor 2. I’ve changed out all 4 exhaust sensors with brand new Denso units, I’ve pressure tested and smoke tested the exhaust and found no leaks. I’ve tested and ohm’d out the harness between these sensors and the ecu, all at factory specs. I’ve also swapped the sensors across banks to no change. I’ve pressure tested and smoke tested the intake manifold as well and found some small leaks that I was able to fix, still had the same codes come up. What I can’t wrap my head around, is the fuel trims. They mimic the error codes with one bank lean and one bank rich. And what is happening is shuddering at idle like it has a vacuum leak and about to stall. I have the Torque app to monitor the fuel trims as I drive and can see the exhaust sensors respond appropriately to load, but they bias their voltage readings, Bank 1 high and Bank 2 low. I’ve attached a screenshot to give a better understanding.

    I’d like to think that my fuel pump is going out, but the truck runs fine except for idle and pulls fairly strong. I also lean towards injectors because of mileage, but I’m not certain that new injectors would fix it. Any thoughts or ideas are appreciated. Thank you!

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