I'm really wondering what P3fff means?
My car has 130000 miles.
My car has an automatic transmission.
The P0134 code means that the air fuel ratio sensor is not operating. Most of the time it will need replacing to correct. The P0327 code means that your knock sensor is not getting enough voltage. The P03FF may indicate an internal failure of the ECU. It is possible that the ECU issue is causing the other sensors to malfunction.
If you’d like to get your car fixed, a certified technician, like one from YourMechanic, can perform some tests to further diagnose your trouble codes and determine the exact cause of your concerns. Best of luck.