I replaced the defective original EGR on my 2008 3.8L with 140k mi. The replacement, an aftermarket unit, kept throwing P1404 codes which refers to a close position error. This error kept reoccurring every 20 miles or so, for over a week, and roughly 200 miles. I was inclined to blame the part, but upon reading various internet info, I concluded that the battery should be disconnected to allow the engine computer to reset and re-learn.

Sure enough, disconnecting the battery for a few seconds allowed ther engine computer to immediately adapt to the aftermarket EGR. It works fine now, no codes.

To those replacing your EGR, make sure to disconnect the battery to help with EGR position calibration.

 

after relearning process, code still came back on...what other possible issues would cause code reoccurance?