Trouble Code

HO2S Heater Resistance Bank 2 Sensor 2

The oxygen sensor is a mandatory factor that is used to regulate the performance of the engine. Oxygen sensors only regulate the engine performance after the sensors reach a certain temperature. A proper working engine generally takes 15 minutes to reach the required temperature.

The reading of the oxygen cylinder is needed just after the engine runs. The internal heaters are aligned with the sensors to heat up them more quickly than the engine. The monitor of the vehicle will acknowledge the temperature of the oxygen sensors by computing the resistance of the oxygen sensor. If the resistance of the oxygen sensors is out of the range the monitor will guess that the oxygen sensor is giving unsatisfactory results.

Like other several codes, P0060 is a DTC code that is generated when there is an issue in the operation of the oxygen sensor’s heater circuit.

What does the P0060 code mean?

If your vehicle is generating P0060 code, it means that the powertrain control module is detecting a problem in the heater circuit of the catalytic convertor oxygen sensor bank 2. Bank two implies that there is an issue in the bank of the engine that does not contain cylinders.


Zirconium oxide is used as a sensing element that is coated with vented steel that is used to resist your O2 sensor. Platinum electrodes connect the sensing elements to the wires leads in the oxygen sensors harness. The oxygen sensor sends information to the PCM about the percentage of the oxygen particle in the engine exhaust comparing with the oxygen particle in the ambient air. That information is used by PCM to analyze the fuel delivery and the ignition timing of the engine.

The hot oxygen sensors use the battery voltage to preheat in the cold start condition. Voltage is supplied to the oxygen sensors until they reach a certain temperature and PCM enters closed-loop operation. Voltages route through the PCM with the help of fuses when the ignition switch is turned on during the cold start phase.

The PCM discontinues flowing of voltage to the oxygen sensors once the engine reaches the normal operating conditions. And when PCM detects a level of resistance in your oxygen sensor is higher than the particular range, it will generate the error code.

Possible causes of P0600 code

  • Fusible Blown oxygen sensor
  • The problem in the PCM
  • Faults in open circuit harness
  • The problem in oxygen sensors
  • Loss of relay response from engine to throttle
  • Hard starting engine

Symptoms of P0060 code

  • The poor economy of fuel consumption
  • Engine misfire at idle condition
  • Check engine light on
  • Poor work performance of engine until reaches operating temperature
  • Black fuel exhaust

How can the P0060 code affect vehicles?

The emission system computes the emission output through the reading of the oxygen sensors. The monitor of the vehicle will adjust the emission output according to the reading of the oxygen sensors of the vehicle.

If there are problems in the oxygen sensors of the vehicle, it will emit a higher amount of emission fuel which will cause a bad affect on the environment. Also if the emission level increases it will affect the life span of the catalytic convertor.

How to diagnose the P0060 code?


It is easy to diagnose the error of this code. To diagnose the cause of P0060 Error code generation we need to check out the sensor wiring and also diagnose the circuits through the oxygen sensors. The internal parts of the circuits may be the possible reason for this code. So, all areas must be diagnosed thoroughly to detect. If you are a beginner you can use the manual or the booklet provided with the vehicle to detect the problem. You can do the required repairs by yourself or you can go for a mechanic.

How to troubleshoot the P0060 error?

The causes of the error code vary from vehicle to vehicle. Take your ride to the garage and get proper to take care of your vehicle with the professionals.

Trouble Code

P0420 Code: Catalyst System Efficiency below Threshold (Bank 1)

When your check engine light illuminates with the P0420 code, it means that an expensive trip to your automobile.

P0420 error code indicates that the catalytic convertor of your vehicle is underperformance and it needs proper attention.

Definition of P0420 error code

According to DTC P0420 can be defined as Catalyst System Efficiency below Threshold (Bank 1).

What exactly P0420 code is?

P0420 error code indicates that there are faults in the catalytic convertor of the vehicle. The primary function of the catalytic converter is to breakdown harmful polluting elements such as carbon monoxide, hydrocarbons, and nitrous oxide during the combustion cycle. The catalytic converter uses platinum and gold meshes to filter the exhaust fumes and thus reduce the expelled emission from the exhaust pipe.

These metals act as a catalyst and participate in the chemical reaction that turns hydrocarbon into water and carbon dioxide, carbon monoxide into carbon dioxide, and nitrous oxide into nitrogen and oxygen.

The catalytic converter uses two oxygen sensors, in which one is fixed upstream while the other is positioned downstream.

When the upstream oxygen sensor works properly in the closed-loop its reading will ideally fluctuate from the initial stage. The reading of the downstream will not change and it will remain the same as in the initial stage.


When both oxygen sensors show similar readings, it indicates that the catalytic converter is underperformance. When the oxygen level is high, then the voltage of the rear oxygen sensor decreases and fluctuates like the front oxygen sensor and powertrain control module stores the P0420 error code and turns the engine check light on.

Possible causes P0420 error code

  • Open or burnt oxygen sensor wiring
  • Bent or corroded oxygen sensor pins
  • The front oxygen sensor is not working properly
  • Faulty rear oxygen sensor
  • Faults in catalytic convertor
  • Leakage in an exhaust pipe

Possible symptoms of P0420 error code

  • Check engine light illuminates or blinking
  • Poor engine performance
  • Failed fuel economy
  • Increment in emission fuel
  • Clogged catalytic converter
  • Foul smell from the exhaust pipe

How serious is the P0420 error code?

With the P0420 error code in your vehicle the no driveability condition arrives. You are unable to notice the symptoms of this error code except that the check engine light is on. If this error does not get proper treatment, this can cause various damage issues to other components of the vehicle.


The main issue with this error code is in the catalytic converter, if the catalytic converter is not diagnosed timely, it can be seriously damaged. So you need to diagnose the root cause of P0420 and get it to repair as quickly as possible.

How to diagnose the P0420 error code?

Mechanic follows these steps to diagnose the P0420 error code:-

  • Uses an OBD-II scanner to recover error codes stored by PCM
  • Diagnose the live information of the downstream sensor to determine whether it is working properly or not.
  • Diagnoses all the codes that can generate the P0420 error code.
  • Repair misfires, ignition problem, and fuel system problem if required
  • Take the vehicle to test drive to detect freeze frame data to determine whether the rear sensor is working properly or not.
  • Check the catalytic converter from the available updates of PCM. And if required replace it and updates to PCM.

How to fix the P0420 error code?

Depending on the diagnostic results, you need to do the following steps:-

  • Replace oxygen sensors
  • Replace catalytic converter
  • Replace both sensors(if required)

The primary step: ensure that the ignition switch is off and then disconnect the battery of the vehicle.

Remove the connections of the sensors: remove the connection of the sensors to protect from the accidental burn.

Remove old catalytic converter: if you notice that the catalytic converter is damaged, remove the old one. Some catalytic converters are screwed to exhaust pipe using bolts or sometimes they are welded. You need to cut the welded pipe or unscrew the bolts.

Install new catalytic converter: remove the old catalytic converter and replace it with the new one. Use a good torque wrench to install as it can break easily if overtightened.

Most probably, an oxygen sensor fails, and the P0420 error code returns. You need to contact a professional to see your vehicle has a manufactures warranty related to emission parts.