The DPFE is more than likely the cause of the P0401 code. It is located at the rear passenger side of the engine, It is easily replaced. Cost is around 35 to 40 dollars. A picture is attached. The EGR valve is usually not the problem. But it is located on the passenger side of the throttle body area.
2 YR Notes: **Caution!!** Before replacing the EGR Valve, inspect the DPFE/EGR Valve Pressure Feedback Sensor and hoses for proper operation. It is common for a DPFE sensor to set a trouble code
Tuesday, August 18th, 2009 AT 6:54 PM