dealer cannot get that engine light to stay off.. code is p401 put new egr on and if it sits for 2 days it will go off for about 10 miles an pops back on , dont no what to do.

 

Your dealer obviously has all this info but you can read through it FYI....

If they replaced the EGR cooler I would think one of the 3 pressure sensors would be the next logical step, IDK.

P0401 - Exhaust Gas Recirculation (EGR) Flow Insufficient Detected
<TABLE border=1 cellSpacing=0 cellPadding=3><TBODY><TR><TH vAlign=bottom align=middle> </TH><TH vAlign=bottom align=middle> </TH><TH vAlign=bottom align=middle> </TH><TH vAlign=bottom align=middle> </TH><TH vAlign=bottom align=middle> </TH></TR><TR><TD style="BORDER-RIGHT: medium none" vAlign=top align=left>Description: </TD><TD style="BORDER-LEFT: medium none" vAlign=top colSpan=4 align=left>Estimated EGR percent is less than the minimum limit for the operating conditions. This DTC sets when the pressure ratio of the manifold absolute pressure (MAP) sensor signal and the exhaust pressure (EP) sensor signal across the EGR valve is not as expected. </TD></TR><TR><TD style="BORDER-RIGHT: medium none" vAlign=top align=left>Possible Causes: </TD><TD style="BORDER-LEFT: medium none" vAlign=top colSpan=4 align=left>

• Aftermarket intake systems or exhaust systems
• Restricted air flow (intake or exhaust)
• Restricted EGR cooler
• EGR valve position sensor bias
• Exhaust pressure (EP) sensor bias
• Manifold absolute pressure (MAP) sensor bias
• Damaged EGR valve

</TD></TR><TR><TD style="BORDER-RIGHT: medium none" vAlign=top align=left>Diagnostic Aids: </TD><TD style="BORDER-LEFT: medium none" vAlign=top colSpan=4 align=left>The presence of this DTC may indicate that the vehicle is operating in derate mode and may experience a loss of power. </TD></TR><TR><TD style="BORDER-RIGHT: medium none" vAlign=top align=left>Application </TD><TD style="BORDER-LEFT: medium none" vAlign=top align=left> </TD><TD vAlign=top align=middle>Key On Engine Off </TD><TD vAlign=top align=middle>Key On Engine Running </TD><TD vAlign=top align=middle>Continuous Memory </TD></TR><TR><TD style="BORDER-RIGHT: medium none" vAlign=top align=left>All </TD><TD style="BORDER-LEFT: medium none" vAlign=top align=left> </TD><TD vAlign=top colSpan=3 align=middle>GO to Pinpoint Test W . </TD></TR></TBODY></TABLE>