Hi, over the last two months......
Dropped off Avy for transmission repair for slipping in overdrive. 8 hours later the shop said ready for pickup. I asked if they rebuilt the tranny they said yes and gave me a one year warrant.
couldn't drive truck home. Engine misfiring, rough running at all rpm, check engine light flashing, Transmission shop agreed to repair the truck, ps they had another Avy in the yard with engine misfire, interesting.
After a week at trans shop the owner called and reported he couldn't fix it and offered a discount.
took truck to nearby licensed Napa repair shop, they told me bad o2 sensor and high back pressure in exhaust. they refused aftermarket parts so I took to another shop to save a buck, new after market cats and bosh 02 sensors installed. drove it home.
3 days later CE light and engine misfire. I decided to look into the problem myself. bought a launch x431 scan tool
scan tool says all 4 02 sensors failing for heater resistance. and bank 2 sensor 1 no activity.
I found a service manual online. checked for voltage at pink wire at sensor from PCM, Good on all 4.
Checked for amps at all sensors via scan tool, scan tool show .8 amps on all 4 02 sensors.
then, using the troubleshooting manual

1. Connect a test lamp between the ignition 1 voltage circuit of the HO2S harness connector on the engine harness side and the HO2S heater low control circuit of the HO2S harness connector on the engine harness side.
2. Command the HO2S heaters ON with a scan tool.

Does the test lamp blink once per second? Yes it does,
then it says to check for 3 ohms in the circuit, Im not sure what they mean here.
checked sensors for shorts and resistance, the bosh heaters are 12 ohms resistance.
bought a Denso 02 sensor, the Denso heater is 5 ohms resistance, is this the problem?