P2000 - NOX TRAP EFFICIENCY BELOW THRESHOLD BANK 1

When the DTC P2000 OBDII code is stored, it means that the vehicle’s computer detects a level of nitric oxide (NOx) above the allowable range.

In internal combustion engines, NOx is produced as an exhaust emission. To reduce these emissions, a catalytic converter (TWC) is used, but taking into account that the TWC is not as effective in gas-burning engines, a NOx trap or NOx absorption system is used. This process is known as the Selective Catalytic Reduction (SCR) system.

In the SCR system, Nitrogen Oxide (NOx) sensors are used in the same way as Oxygen (O2) sensors in gasoline engines. They monitor the NOx particles. In turn, the PCM (Powertrain Control Module) relies on the NOx Sensor and Catalyst data to calculate the NOx trap efficiency.

• Check Engine light ON.
• An excessive amount of smoke comes out of the exhaust.
• Engine performance decreases.
• High engine temperatures.
• Reduced fuel economy.

The reasons to store the P2000 OBD2 diagnostic code:

• The NOx trap may be defective or overloaded.
• The diesel exhaust fluid injection system may be damaged.
• The NOx reducing fluid provided may not be suitable.
• The Exhaust Gas Recirculation (EGR) system may not be operating properly.
• Exhaust leaks in the NOx trap.

Steps to troubleshoot the P2000 OBDII fault code:

• Consult Technical Service Bulletins (TSB).
• Check the cables and connectors associated with the system because cables are close to exhaust components, they are exposed to high temperatures. Likewise, connector terminals often have corrosion. Repair or replace as required.
• Check the exhaust system for leaks. If so, make the respective repairs.
• Check the Selective Catalytic Reduction system tank, and check that the installed reducer is working properly. Replace it if necessary.
• Check the correct operation of the Exhaust Gas Recirculation If you find other codes related to this system stored, you should diagnose them. Also, take into account that the elimination of the EGR valve results in a malfunction of the trap.
• Make sure that the NOx Sensors are working properly. Make the appropriate adjustments.