Subaru P0030, Open loop, No FT data AF Sensors read 3.79

I’ve been dealing with poor fuel economy and a intermittent P0030. The vehicle is a 2002 Subaru Outback 3.0 H6, the vehicles stays in open loop even after reaching operating temperature of 190-200 F. Short and long term fuel trims never become active, they stay at 0.0 The vehicle uses two Air Fuel Ratio sensors, 1 on each bank upstream of the catalytic converters and a 02(narrow band) sensor after the y pipe/downstream cat. The AF sensors stay 3.79v in the live data and don’t change under any circumstance. I’ve watched several PHAD and Scanner Danner videos on 02 sensors but have not seen them come across zero fuel trim data.I don’t know where to start, any help is appreciated. Thanks!

I’m using a simple handheld Bosch scanner in generic obd2.

Monde wrote:

Try checking both front Air/fuel sensors heater resistances for a start.

I went and checked the resistance. The meter doesn’t read anything across the two black wires on the bank that is triggering the CEL. On bank 2, I’m getting a 1.4 ohm reading. The bank 2 sensor looks newer than the bank 1 sensor which has made in Japan etched onto it. This vehicle doesn’t not have a MAF, if the bank 1 sensor is bad shouldn’t I still be getting some fuel from readings? I created a vacuum leak to see if I would see the fuel trims react. It had zero effect.