The code PO404 on a 2000 Mazda Millennia 2.3 means that there is something wrong with how the vehicle is processing the oxygen it needs for combustion. This would mean an oxygen sensor or solenoid is bad. This vehicle has two oxygen sensors.
2001 Mazda millenia
how to change speedometer sensor on mazda millenia 2000 2.3 v6
The Mazda millenia from 2000 gets 20 mpg, 28 on the highway, and 25 on average.
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a Mazda millenia with a miller cycl engine 2.3 engine has 6 igition coils
millenia starting with my 2001 had cabin filters. 2000 my and before no hava
Trouble code P0404 means: Exhaust Gas Recirculation Control Circuit Range/Performance
Button on the shifter.
air conditioning
It depends on what model of Mazda you have. My 2000 Mazda millenia doesn't. It does have reverse teeth though. I would have to go to a dealer to get another one made for it.
Check Engine code of P0404 (EGR)
in the fuel tank. you gotta drop the tank