Keep the fuel system reading the exhaust accurately with the Walker Products Oxygen Sensor 350-35021. This is an upstream (pre-catalytic-converter) oxygen sensor that installs as a direct-fit replacement for the 2009-2013 Mazda 6. Mounted in the exhaust ahead of the catalytic converter, it measures the oxygen content of the exhaust gas and sends that signal to the engine control unit, which uses it to trim the air-fuel ratio for proper combustion feedback.
Signs the original upstream sensor may need replacing include a stored oxygen-sensor trouble code, a lit check-engine light, rough running, or reduced fuel economy. Because those symptoms can have other causes, diagnose the fault before replacing. If a failed upstream oxygen sensor is confirmed as the cause, this sensor replaces it.
Manufacturer part number: 350-35021 (also 35035021).
What does this oxygen sensor do?
It measures the oxygen content of the exhaust and sends that signal to the ECU, which uses it to adjust the air-fuel ratio for proper combustion feedback.
Is this an upstream or downstream sensor?
It is an upstream sensor, mounted in the exhaust ahead of the catalytic converter to monitor oxygen for closed-loop air-fuel ratio control.
What vehicles does the Walker 350-35021 fit?
It is a direct-fit replacement for the 2009-2013 Mazda 6. See the Buyer's Guide tab to confirm the fit for your specific vehicle.
How do I know if my oxygen sensor needs replacing?
Common signs include a stored oxygen-sensor code, a check-engine light, rough running, or reduced fuel economy. Diagnose the cause first, since other faults can produce these symptoms.
Will replacing this sensor fix my check-engine light?
If a failed upstream oxygen sensor is confirmed as the cause, this sensor replaces it. Have the code diagnosed first, as the light can be triggered by other issues.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
