2426247PE | Genuine Paccar® Brake Pressure EGR Control Valve

1. Reduce NOx emissions

• NOx forms when combustion temperatures are very high.

• The EGR control valve recirculates a portion of exhaust gases back into the intake, diluting the air/fuel mixture and lowering combustion temperature.

• This helps the vehicle meet emissions regulations, such as those from the United States Environmental Protection Agency.

2. Improve fuel efficiency

• By lowering combustion temperature and controlling exhaust flow, the EGR valve optimizes engine efficiency under certain driving conditions.

3. Reduce engine knock

• Lower peak temperatures reduce pre-ignition or knocking, especially in gasoline engines, which protects the engine over time.

4. Balance performance and emissions

• The EGR valve opens and closes based on engine load, speed, and temperature to allow the right amount of exhaust gas.

• This ensures the engine runs smoothly while keeping emissions in check.

1. Rough idle or stalling

• If the EGR valve sticks open, too much exhaust gas enters the intake, causing the engine to idle roughly or even stall.

• If it sticks closed, NOx emissions increase, and the engine may run hotter than normal.

2. Reduced engine performance

• Hesitation, sluggish acceleration, or loss of power can occur because the EGR system is not regulating exhaust gases properly.

3. Increased fuel consumption

• A malfunctioning EGR valve can disrupt the air/fuel mixture, making the engine burn more fuel.

4. Engine warning light

• The check engine light (CEL) or emissions warning light may illuminate.

• Diagnostic trouble codes (DTCs) like P0401, P0402, P0403 often indicate EGR flow or valve issues.

5. Black or white smoke from exhaust

• Too much unburned fuel or improper combustion can cause black smoke (diesel) or white smoke (gasoline).

6. Engine knocking or pinging

• In gasoline engines, a stuck or malfunctioning EGR valve can cause pre-ignition, resulting in knocking or pinging sounds.

7. Failed emissions test

• A bad EGR valve can cause high NOx emissions, leading to failure in emissions inspections.