Trouble code P0403 means: Exhaust Gas Recirculation Control Circuit Replace the EGR valve
Exhaust Gas Recirculation Sensor "A" Circuit High. Replace Sensor The sensor is part of the egr valve. Replace the valve.
Trouble code P0401 means: Exhaust Gas Recirculation Flow Insufficient Detected replace the EGR valve Trouble code P0446 means: Evaporative Emission System Vent Control Circuit
its a exhausts gas regulator Exhaust gas recirculation valve. You usually need to replace it.
Insufficient EGR (exhaust gas recirculation) valve. Suggest you replace the valve.
replace the EGR valve and reset the OBD II Exhaust Gas Recirculation valve
This issue is typically caused by a broken or jammed EGR (Exhaust Gas Recirculation Valve). To remedy the problem, you must remove the old EGR valve and replace it. Attached is an Article from AutoZone on how to determine if it is the EGR valve and how to replace the EGR on a Generation 3 (1996-1999) Ford Taurus, It will also determine if your problem lays in other EGR components.
Trouble code P0401 means: Exhaust Gas Recirculation Malfunction Replace the EGR Valve
Trouble code P0402 means: Exhaust Gas Recirculation Flow Excessive Detected Replace EGR valve
The car may not be approved at the "car approval station". Maybe you can clean it from soot, it depends on what car you own. EGR= Exhaust Gas Recirculation. It is good for the environment.
P0401- Exhaust Gas Recirculation insufficient flow. Probably need to clean or replace your EGR valve located on the back of your intake.
P0403 Exhaust Gas Recirculation Circuit Malfunction Try cleaning the EGR Valve and see if that helps. If not, you may have to replace the EGR Valve. Also make sure all vacuum hose are connected and are not broken or have a leak.