What causes a P1133 code?

P1133 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 P1133 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1133 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

Log in Sign up

OBD-II

P1133

A/F Sensor Circuit Response Malfunction

What it means

The Air/Fuel ratio sensor is not switching fast enough.

Sign in to view symptoms, probable causes, diagnostic steps, severity, and related codes

Log in Sign up free