DTC P2BED-00: Fuel Control System 'A' Too Rich Bank 1: General Description

The A/F ratio feedback control is the control that regulates the amount of fuel injection by detecting the rich and lean of the exhaust gases by installing oxygen sensors in the exhaust gas so that they become combustion at the theoretical A/F ratio in order to increase the purification efficiency of the three-way catalyst. In general, emissions of NOx are increased if emissions are lean and CO and HC emissions are increased if they are rich. Therefore, in order to purify them effectively using the 3-way catalyst, they must be controlled for A/F ratio control. However, the range of A/F ratio that can purify all of them is extremely narrow, so feedback control is carried out using oxygen sensors for precise control. It utilizes the characteristics of rapid change of output signal near the theoretical air ratio of oxygen sensor. Since the correction characteristics are adversely affected by many factors, the calibration value of feedback during normal operation of the engine is treated statistically for a long period of time and A/F ratio control is performed.