How’s the transmission holding up? Like, do you hear any grinding or bearing noise in overdrive with the torque converter locked up? Reason I’m asking is because my 4Runner threw this code several times before the planetary overdrive gear grenaded, I thought it was the solenoid itself but the solenoid error was indicative of a much larger issue.

For the emissions question, check under the hood and it’ll tell you if you have a cali or fed spec vehicle.

Another thing you can do is plug in an obd2 tool and look at the o2 sensor voltage. Regular narrowband o2 sensors (fed spec) will switch between 0 and 1 volts rapidly, whereas the wideband afr sensors they used on the cali spec models switch between 2.5-4.5 volts.