What causes a P1707 code?

P1707 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a P1707 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1707 active.

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

OBD-II

P1707

O2SPD Lambda sensor NOx plausibility low fault

What it means

The engine control module (ECM) has detected that the reading from the NOx sensor (Outlet) is not plausible compared to the expected values based on the SCR system's operation and the reading from the inlet sensor.