Fault code P200F – catalyst system over temperature (Bank 2)

Fault code P200F is called “Catalyst System Over Temperature (Bank 2)” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P200F

This diagnostic trouble code (DTC) is defined as overheating of the catalyst system (Bank 2). It is set when the catalytic converter temperature on Bank 2 exceeds the maximum allowable temperature.

The catalytic converter is designed to remove harmful exhaust emissions such as hydrocarbons, carbon monoxide and nitrogen oxides. Removal occurs by oxidizing these substances as they pass through a heated catalyst.

For the conversion process to take place, the catalyst must have a certain temperature. This temperature typically ranges from 390°F, to 1600°F at maximum efficiency.

The PCM uses inputs from the oxygen O₂ and air/fuel ratio sensors. As well as special sensors that measure the temperature of the exhaust stream before and after the catalyst. To control the required catalytic converter temperature for effective cleaning.

The control module compares the switching speeds of the front and lower oxygen sensors O₂. This data is then compared to the actual exhaust gas temperature both before and after the catalytic converter.

If the exhaust temperature exceeds the set upper limit, the PCM will consider that the converter is in overheating condition. The code P200F is then set and the warning light will illuminate as a result.

In some cases the PCM may reduce engine power, go into emergency mode, or even shut down the engine. To protect the catalytic converter from further damage.

The PCM usually allows the engine to restart after the catalytic converter has cooled sufficiently. But sometimes the emergency mode may remain until code P200F is eliminated.

Symptoms of vehicle malfunctions

The main signal that an error P200F has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

1. The “Check engine” control lamp on the control panel will light up (the code will be stored as a fault).
2. Other related fault codes may also be present.
3. Increased emission of harmful substances in the exhaust gases.
4. Black smoke coming from the exhaust pipe.
5. Increased fuel consumption.
6. Sometimes there may be no symptoms, despite a stored fault code.

This error is considered moderate if there are no symptoms. But if symptoms are present, the cause of the P200F error should be corrected as soon as possible. Ignoring it can cause serious damage to the catalytic converter.

Factors that can cause this error code

The error code P200F can mean that one or more of the following problems have occurred:

• Damaged or faulty oxygen sensor (O₂).
• Damaged or incorrectly connected oxygen sensor wiring (HO₂S).
• Damaged or leaking exhaust manifold, catalytic converter, muffler, exhaust pipe.
• Delayed ignition timing.
• Oxygen sensors at front and rear of catalytic converter are reporting too similar readings.
• Sometimes the cause is a faulty PCM module.

How to fix or reset OBD-2 code P200F

Some suggested steps for troubleshooting and fix the error code P200F:

1. Read all the error codes stored in the vehicle’s PCM memory with an OBD-II scan tool.
2. Check the operation of the oxygen sensor O₂ located behind the catalytic converter (at the exhaust outlet). Voltage reading of this sensor should be stable.
3. Diagnose other error codes that may have caused code P200F.
4. Troubleshoot engine cylinder ignition timing and fuel system malfunctions.
5. Inspect the oxygen sensor installed behind the catalytic converter (at the exhaust outlet) for wear and damage.
6. Test-drive the vehicle to check the oxygen sensor.
7. Replace or reprogram faulty PCM if necessary.

Diagnose and repair of problems

If there are no additional errors, clear fault code P200F and perform a short test drive. To allow the PCM to go into closed loop mode, then scan the system again and see if the code comes back.

Check the catalytic converter and leaks

Check for exhaust leaks, repair them if necessary. Inspect any electrical connections that are connected to the oxygen sensor. Sometimes the electrical connector may disconnect due to heat and vibration, and the engine error indicator light will come on.

If a code is found, check the operation of the oxygen sensors to make sure they are working properly. Compare the displayed output signals with the values indicated in the manual.

Read the inlet temperature reading of the transducer and then the outlet temperature reading. The difference between the input and output temperatures should be about 100°F. If the temperature difference approaches 200°F or reaches 500°F. Most likely the catalytic converter is damaged.

Test the temperature sensor, inspect the wires

Check the wiring harness that goes to the temperature sensor. It’s important to make sure there are no burned out, torn or severely loose spots. Which could hit any moving component while the car is in motion.

Check the operation of the temperature sensor by thoroughly warming up the engine. Remember that the sensor will only work once it has reached its operating temperature.

Connect the sensor output to a multimeter and run the engine at about 2000-2500 rpm. The output should show a voltage fluctuating between 0.1 and 0.9 V. If the sensor output does not change or the response time is too long. This means you have a bad sensor, you should replace it.

Replacing the temperature oxygen sensors will most likely fix the error. But sometimes, you need to replace the catalytic converter to fix the problem. If the code P200F is combined with other codes, try fixing the other codes first.

On which vehicles does this problem occur most frequently

Fault code P200F can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

• Ford
• Hino
• Mercedes-Benz
• Volkswagen

Fault code P200F can sometimes be found with other errors. The most common are the following: P0425, P0426, P0427, P0428, P200E.

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