A technique is provided for compensating an untrimmed oxygen (O2) sensor utilized in operation of an exhaust gas recalculation (EGR) system associated with an engine. The technique includes, in one implementation, receiving a measurement from the O2 sensor at a known pressure, where the O2 sensor is positioned on an intake side of an engine system. Humidity compensation and pressure compensation are then determined for the O2 sensor measurement, where the pressure compensation is based in part on the humidity compensation. The EGR system is controlled using the untrimmed O2 sensor measurement that has been compensated for pressure and humidity.