Mazda CX-9 P0405: EGR Sensor “A” → Circuit Low
P0405 is a generic OBDII trouble code. It deals with the signal coming from the EGR system. Since it is a generic code, it has the same meaning for the Mazda CX-9 as it would any other vehicle. The EGR system allows a certain amount of the CX-9’s exhaust to re-enter the combustion chamber, … Read more