I have p0155 code for oxygen sensor

You made the classic DIY mistake--replacing whatever part is listed in the trouble code without doing any diagnostic work. P0155 relates the o2 sensor HEATER circuit. That can be caused by an open wire or a blown fuse. Until you fix that, the oxygen sensors won't work properly and that can cause a P0432. First fix the P0155 issue

Then fix the P0455 Evaporative Emission Control System Leak Detected (gross leak) issue. THEN see if the P0432 goes away.

• Defective Oxygen Sensor/Air Fuel Ratio Sensor Heater element(s)
• Defective Oxygen Sensor/Air Fuel Ratio Sensor Heater circuit
• Defective Engine Coolant Temperature Sensor
• Defective sensor wiring and/or circuit problem
• Defective Oxygen Sensor/Air Fuel Ratio Sensor Heater Relay or Fuse
• PCM software needs to be updated
• Defective PCM

all of those codes listed have a common fault listed and that is the ECM
substitute it with a known good unit and then see what happens

P0155 = 2/1 O2 Sensor Heater Failure, Oxygen sensor heater element malfunction. logic dictates that you replace your O2 Sensor. DIY car obd2 code scanner online shopping

Hi there:DTC P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
This code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155.
A code P0155 may mean that one or more of the following has happened:

• O2 Heater element resistance is high
• Internal short or open in the heater element
• O2 heater circuit wiring high resistance
• open or short to ground in the wiring harness

Possible Solutions

• Repair short or open or high resistance in wiring harness or harness connectors
• Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)

Use this link on previous answer to check diagra location.


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DTC P0133 - Oxygen Sensor Circuit Slow Response (Bank1, Sensor1)
This involves the front oxygen sensor on Bank 1. This code indicates the engine air fuel ratio is not being adjusted by the oxygen sensor signal or the ECM as expected to do so, or not adjusted as often as expected to do so once the engine is warmed or under normal engine use. You will likely not notice any drivability problems, although there may be symptoms.

A code P0133 may mean that one or more of the following has happened:
The oxygen sensor is faulty
The wiring to the sensor is broken / frayed
There is an exhaust leak


DTC P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
This code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155. See also: P0135 (Bank 1). You will likely notice poor fuel economy the illumination of the MIL.

A code P0155 may mean that one or more of the following has happened:
O2 Heater element resistance is high
Internal short or open in the heater element
O2 heater circuit wiring high resistance
open or short to ground in the wiring harness


DTC P0306 - Cylinder #6 Misfire Detected
A P0306 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #6. Symptoms may include the engine may be harder to start, the engine may stumble / stumble, and/or hesitate or other symptoms may also be present.

A code P0306 may mean that one or more of the following has happened:
Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer


DTC P1115 - Intake Air Temperature 2 Circuit High Input (Super/Turbo Charged engines)


In the next diagram could checl this specific location about each O2 sensor...




Hope this helps.

DTC P0133 - Oxygen Sensor Circuit Slow Response (Bank1, Sensor1)
This involves the front oxygen sensor on Bank 1. This code indicates the engine air fuel ratio is not being adjusted by the oxygen sensor signal or the ECM as expected to do so, or not adjusted as often as expected to do so once the engine is warmed or under normal engine use. You will likely not notice any drivability problems, although there may be symptoms.

A code P0133 may mean that one or more of the following has happened:
The oxygen sensor is faulty
The wiring to the sensor is broken / frayed
There is an exhaust leak


DTC P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
This code refers to the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155. See also: P0135 (Bank 1). You will likely notice poor fuel economy the illumination of the MIL.

A code P0155 may mean that one or more of the following has happened:
O2 Heater element resistance is high
Internal short or open in the heater element
O2 heater circuit wiring high resistance
open or short to ground in the wiring harness


DTC P0306 - Cylinder #6 Misfire Detected
A P0306 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #6. Symptoms may include the engine may be harder to start, the engine may stumble / stumble, and/or hesitate or other symptoms may also be present.

A code P0306 may mean that one or more of the following has happened:
Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer


DTC P1115 - Intake Air Temperature 2 Circuit High Input (Super/Turbo Charged engines)


In the next diagram could checl this specific location about each O2 sensor...




Hope this helps.

The only codes on your car that are only Ford codes are the one ranging in the 1000,s your codes start with 0,s there fore they are generic OBD2 codes
P0135=O2 Sensor Heater Circuit
P0155=O2 Sensor Heater Circuit
P0304=Cylinder 4 Misfire Detected
P0172=System Too Rich

P0155 OBDII code refers to HO2S heater circuit - bank 2 sensor 1 , not knowing your engine size and engine vin code thats about as far as we can go with our answer . we can say bank 2 sensor 1 is the passenger side upstream oxygen sensor has a heater circuit problem , could possibly be a bad oxygen sensor . you ask what is that - thats what it is ... cheers .

P0155 - Heated Oxygen Sensor Heater Circuit (bank 2, sensor 1)

bank 2 sensor 1 (front, driver side) o2 sensor needs to be replaced