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Q: What exactly does the code P3fff mean?

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The check engine light is on. It drives fine. It shifts fine,it drives with no hesitation. But it failed emissions with 2 P3fff codes. Plus, "exhaust gas recirculation flow insufficient detection" and "mass or volume air flow circuit range/performance problem". It makes a high pitch whine when I put it in reverse. Does not whine as I drive.

My car has 80000 miles.
My car's transmission is unknown to me.

Hi there. The code P3fff means that there is an issue with the PCM (the computer to the vehicle). The codes regarding gas recirculation flow and mass air flow are coming on either due to the PCM failure or due to the fact that the EGR valve and MAF sensor has failed. Check the EGR valve for burned wires and to determine if the valve is working. Take the valve off, clean it out, and then put it back on with a new gasket.

Then, check the MAF sensor and see if there are any burned wires and if the sensor is clean. The whine could be the reverse gear in the transmission, which may use the type of gear that always whines, which would be a normal condition. If you need further assistance troubleshooting your vehicle, then seek out a professional technician, such as one from Your Mechanic, who can come to your location to determine why the service lights are on and what repairs are needed.

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