Technical Description of OBD-II Trouble Code
The circuit for the Exhaust Gas Temperature EGT Sensor in Bank 1 Sensor 1 is experiencing intermittent issues.
What does that mean?
This is a generic powertrain code that is applicable to most makes and models manufactured from 1996 onwards. This code can be found in various brands such as Ford, Dodge / Ram, Mercedes-Benz, Alfa Romeo, GMC, Chevrolet, Smart, VW, Audi, etc. However, the specific troubleshooting steps may vary depending on the vehicle.
The diagnostic trouble code (DTC) P2081 pertains to the condition of the EGT (exhaust gas temperature) sensor located in the “up” pipe before the catalytic converter. Its main purpose is to protect the converter from damage caused by excessive heat. This code indicates that there is an intermittent fault in the circuit.
This P2081 DTC refers to Bank #1, which is the side of the engine that contains cylinder #1. Most late model gas or diesel engines are equipped with an EGT sensor. It functions as a heat sensitive resistor that converts the exhaust temperature into a voltage signal for the computer. One wire receives a 5-volt signal from the computer, while the second wire serves as the ground.
The resistance to ground decreases as the exhaust temperature rises, resulting in a higher voltage. Conversely, the resistance increases as the temperature decreases, leading to a lower voltage. If the engine detects a low voltage, the computer will adjust the engine’s timing or fuel ratio to maintain an acceptable temperature within the converter.
Here is an example of an EGT exhaust temperature sensor:
In a diesel engine, the EGT is used to determine the timing of regeneration of the DPF (diesel particulate filter) based on the temperature rise.
If a catless up pipe has been installed and the catalytic converter has been removed, there is usually no provision for the EGT sensor. If there is a provision, it will not function correctly without back pressure, resulting in the code being set.
Symptoms
The check engine light will illuminate, and the computer will store the code P2081. No other noticeable symptoms will be present.
Potential Causes
The possible causes for this DTC may include:
P2081 Repair Procedures
Another reason for this code to be set is if the catalytic converter has been replaced with a catback system. In most states, this is considered an illegal procedure and can result in a significant fine if caught. It is advisable to check local and state laws regarding the removal of this system, as it leads to uncontrolled emissions into the atmosphere. While this may temporarily resolve the issue, it is our responsibility to contribute to keeping the atmosphere clean for future generations.
Until this issue is repaired, the code can be reset by purchasing a 2.2 ohm resistor from any electronic store for a minimal cost. Simply remove the EGT sensor and plug the resistor into the engine side electrical connector. Secure it with tape, and the computer will recognize that the EGT is functioning properly.
