four codes po155 po161 po135 po141 on 2003 kia sedona

Question

I have four codes at the same time, po155 po161 po135 po141. Engine runs fine but poor gas mileage and check engine light is on.

Answer 1

P0155 H02S heater circuit malfunction (Bank 2 Sensor 1)

P0161 H02S heater circuit malfucntion (bank 2 Sensor 2)

P0135 H02S heater circuit malfunction (bank 1 Sensor 1)

P0141 H02S Heater circuit malfunction (bank 1 Sensor 2)

When the upsteam 02 sensor are not working properly the rear which monitor the condition of the catalytic also codes up. The purpose of the 02 sensor is to maintain fuel control, and this is why you have a high amount of fuel comsumption. Because you have a four sensor heater failure check the fuse for the heater circuit which is located in the engine fuse box listed as O2 sensor (UP) and O2 sensor (DN) this is a 15 amp fuse ,