Bad Air/ Fuel mixture sensor warning for ALL Yaris owners

[TheSilkySmooth]

Originally Posted by Return of the Yarii

I have an 07 Sedan and mine was crossthreaded, found out when I did DC header install, bought a new one from Ken @ Sparks. Its listed in the classifieds along w/the header.

It is indeed an Air/Fuel Sensor, the O2 sensor is downstream

*pending sale of A/F Sensor to member on the board*

The is all just a matter of semantics but these sensors conduct OXYGEN at various mixtures outputting a voltage in response to the mixture, so the sensor ONLY senses oxygen but the EC can calculate the mixture using E and a couple other variables for cross check. There is no FUEL sensor on a car per se. You have the MAF that indirectly "supposes" air flow through the "cooling" effect of ambient air running over a hot wire "conductor" or foil and adjust voltage across to run in stasis, and MAP that supposes "throttle position" by the reading absolute pressure in the intake manifold typically with a mechanical device sim to a "barometer". Toyota service parts can call it what they want, but the engineers that design it call it a wide band o2 sensor that looks at free oxygen in the pre-catalysis effluent stream. So maybe we call it #1?