98 Infiniti QX4 codes P0325, P0440 & P1448 with check engine on: what would case all 3 codes?

Question

I have a 98 Infiniti QX4 I know the knock sensor doesn't cuz the check engine light. But as I'm driving and stop at a stop light the rpms drop and it almost stalls.  Would the others codes be making this happen?

Answer 1

HI there,

As you know, the P0325 code has likely been in the system a long time. It's not related to the other 2 codes.

The P0440 code is a catch all code for the evap system. Basically the computer knows there is a leak but doesn't know where. The good news is the P1448 code is for the vent control valve.

If the vent control valve is stuck open, then it creates a leak so the P0440 code will appear with it. Replace the vent control valve and it should resolve both codes.