Methods and systems for a gas constituent sensor

A method, comprising:

• while exhaust gas recirculation is off and over a range of boost pressures:
• generating an intake gas constituent concentration from a gas constituent sensor;
• and
• generating an intake pressure from a pressure sensor;
• and
• based on the gas constituent concentration and the pressure, generating a correction of the gas constituent sensor;
• and
• while the exhaust gas recirculation is on:
• adjusting subsequent output of the gas constituent sensor based on the correction;
• and
• adjusting an amount of exhaust gas recirculation based on the adjusted output of the gas constituent sensor.

A system, comprising:

• an engine with an intake passage and an exhaust passage;
• a turbocharger including a compressor coupled in the intake passage;
• a high pressure exhaust gas recirculation system and a low pressure exhaust gas recirculation system, the high pressure exhaust gas recirculation system having a high pressure exhaust gas recirculation inlet disposed downstream of the compressor;
• a gas constituent sensor positioned downstream of the high pressure exhaust gas recirculation inlet and configured to output a gas constituent concentration;
• a pressure sensor positioned downstream of the exhaust gas recirculation inlet and configured to output an intake pressure;
• and
• a control system in communication with the sensors, the control system including non-transitory instructions to turn off high pressure and low pressure exhaust gas recirculation and generate a gas constituent sensor correction based on outputs from the gas constituent sensor and the pressure sensor, and to adjust amounts of high pressure and low pressure exhaust gas recirculation based on the gas constituent sensor output and the correction when the high pressure and low pressure exhaust gas recirculation systems are on.