Should be a fuse in engine fuse box that powers all 3 of the heaters in the O2 sensors, the computer monitors that heater voltage and no voltage is what sets those codes.
If there was only one O2 sensor with that code then I would suspect wiring or the heater in the sensor was bad.
But all 3 is most likely a blown fuse
That may also solve the Rich codes
The Bank 1 sensor 2's usually lasts the life of the vehicle, it should only "see" clean exhaust being located after the Cat Converter.
The Bank 1 and Bank 2 sensor 1's get the straight exhaust from the engine and are usually OK for 150k miles, spec is 100k.
MPG tends to go down as these O2s wear out, but it doesn't cause major issues, just costs you more money in fuel.
Clean the MAF sensor, always.
Rich code means the computer has cut down fuel injector open time to a pre-set limit(which sets that code) and O2 sensors are still showing less Oxygen content(rich) in exhaust than it should.
Because engine sat for awhile you could have a few fuel injectors that are sticking, letting in too much fuel.
A few because if it was just one then only 1 bank would show Rich code
Run some Seafoam, or similar, injector cleaner in the gas tank that should help clean them up.
On the fuel rail there is a fuel pressure regulator(FPR), passenger side top front of engine, the Return Fuel hose is connected to it, and also a vacuum hose.
Pull off that vacuum hose and check it for fuel, or start engine with it off and see if fuel comes out of FPR, it shouldn't of course.
It it sat dry the rubber in the FPR diaphragm may have cracked and is leaking, and the vacuum line sucks that extra fuel into the intake causing both banks to run rich
Is the exhaust showing black smoke after it is warmed up?
Last edited by RonD; 05-23-2016 at 09:22 PM.