I've replaced the EGR valve, EGR solenoid, EGR pressure sensor, and several vacuum lines. I also performed a fuel and intake port cleaning to remove deposits. Despite these efforts, the vehicle continues to show the P0401 diagnostic trouble code. I'm unsure what else might be causing this issue. Any insights or troubleshooting steps would be greatly appreciated.
Intake EGR passages are prone to clogging, especially in 2000 Ford Contour 2.5L V6 DOHC engines. To access them, you'll need to remove the throttle body and its gasket—there are three ports and one channel that can become blocked. After removing the throttle body and gasket, visually inspect for blockages. A simple test: with the engine running, remove the EGR solenoid cap and cover the air bleed hole with your finger. The engine should run roughly or stall due to reduced EGR flow. If it doesn't, check for vacuum supply to the EGR valve. Disconnect the vacuum hose from the EGR valve and place your finger over the solenoid's air bleed—any vacuum presence indicates a clogged intake passage. This issue is common in many 2.5L Ford engines.
Can you clarify how you cleaned the intake ports? I typically use a wire brush (gun cleaning brush) with sea foam to scrub the passages. This helps clear carbon buildup and improves EGR flow.