Codes P0400 and P0411 in Benz

Joined
Oct 4, 2007
Messages
1,606
Location
Oahu, Hawaii
Check engine light came on in uncles MB and hooked up code scanner and popped up codes P0400 and P0411. P0400: Exhaust Gas Recirculation Flow Malfunction P0411: Sec.Air Inj. Sys. Incorrect Flow Detected I checked on several MB forums and it could be clogged passages. Or could it be something else? I don't want to start throwing parts at it.
 
Joined
Aug 21, 2008
Messages
25,051
Location
ON, Canada eh?
Probably clogged passages. Take the EGR off and have a look. Not sure if your EGR is fully electronic or Vacuum driven. Being a Benz I would imagine it would be electronic and expensive to replace. Take it off and have a look first. If not it could be the flow sensor that is the problem. Is there a way that you can apply voltage/vacuum to make the EGR operate at idle? If so, if the car studders/stalls out the EGR itself is good and it leaves clogged passages or a flow sensor that is the problem. Good luck...
 
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