DTC : P1172: General Description

Courtesy of HONDA, U.S.A., INC.

If a malfunction causes the rear air/fuel ratio (A/F) sensor (bank 1, sensor 1) signal to the powertrain control module (PCM) to deviate from the normal control area, the rear A/F sensor (bank 1, sensor 1) may still become active after the engine starts, but the air/fuel feedback does not start normally and the emissions deteriorate. When the rear A/F sensor (bank 1, sensor 1) output is out of the normal area, and this condition continues after the rear A/F sensor (bank 1, sensor 1) is active, the PCM detects a malfunction and stores a DTC.