Hello expert friends!

Sorry for my poor English, I am from Central America so please understand haha.

I have a Lancer '11 2.0 4B11 with 86k miles, all was going fine until the Engine Service Soon light comes on.

I checked with my obd reader and it shows P0401 EGR insufficient flow, so, I cleaned the electronic EGR in the car, it has carbon build up, after the clean, the engine runs better, the rpms does not hesitate as before, but only passed two days and the same code again.

Somebody knows how the EGR knows about the correct amount of flow here? because I can't see any other sensors related, except the MAP sensor but I can't tell what is the fail.

Thanks for your replies.

 

Hello, if this info is useful for someone, I solved the problem by cleaning all the system with a expensive but good degreaser and cleaning profusely with a steel brush to get all dirt out... after a week of test, the egr is going cool and the Service Engine light was gone

 

If the code returns it may be a popped off or torn vaccum line going to the egr valve and or solenoid.

Also hoses may be routed incorrect