99 Buick Century OBD code P0405

EGR Flow sensor A Circuit Low Input. Checked EGR and mass flow sensor and cleaned. Is this a possible Oxygen sensor replacement. Car runs great.

Please post the size engine you have since different engines have different issues. However, I would check to make sure the passageway to the egr is clean since the flow to the egr is critical. Also there is a possibility that the EGR is bad and may need to be replaced. A cleaning can eliminate the problem but if the valve is bad the problem will remain.

Thanks for the info. I checked air flow and looked ok and took off the ERG and cleaned. Still have the code. I have a problem with the fuel gauge I have posted before. I'll take it in to the dealer and get checked out.