Symptoms
The check engine light will illuminate and the computer will have set code P2034. No other symptoms will be easily noticeable.
Potential Causes
Causes
of this DTC may include:
- Check for loose or corroded connectors or terminals, which is often the case
- Broken wires or missing insulation can cause a direct short to ground
- The sensor may have failed
- A catback exhaust system without EGT provisions installed
- It is possible, but unlikely, that the computer has failed
P2034 Repair Procedures
Lift the vehicle and locate the sensor. For this code, it refers to the Bank 1 sensor, which is the engine side containing cylinder #1. It is located between the exhaust manifold and the converter, or in the case of a diesel, before the diesel particulate filter (DPF). It looks different from oxygen sensors in that it is only a two-wire plug. A vehicle with a turbo will have the sensor near the turbo’s exhaust inlet.
Check the connectors for any abnormalities such as corrosion or loose terminals. Follow the pigtail to its connector and check it as well.
Look for signs of missing insulation or exposed wires that could be shorted to ground.
Unplug the upstream connector and remove the EGT sensor. Check the resistance with an ohmmeter. Probe the two terminals of the connector. A good EGT will have around 150 ohms. If there is very little resistance—below 50 ohms, replace the sensor.
Use a hairdryer or heat gun and heat the sensor while watching the ohmmeter. The resistance should decrease as the sensor heats up and increase as it cools. If not, replace it.
If everything was good at this point, turn on the key and measure the voltage on the engine side of the pigtail. There should be 5 volts at the connector. If not, replace the computer.
Another reason this code may be set is if the catalytic converter has been replaced in favor of a catback system. In most states, this is an illegal procedure subject to heavy fines if caught. It is advisable to check local and national laws regarding the removal of this system as it allows uncontrolled emissions into the atmosphere. It may work, but it is everyone’s responsibility to do our part to keep our atmosphere clean for future generations.
Until this is repaired, the code can be reset by purchasing a 2.2-ohm resistor for pocket change at any electronics store. Simply discard the EGT sensor and plug the resistor into the engine-side electrical connector. Wrap it with tape, and the computer will be convinced that the EGT is functioning correctly.