Ford Diesel codes

[TooMany2count]

My lady friend has a 2005 F250 with a 6.0 diesel while pulling a load over the mountains from California going to Idaho, it through code 404 and 405. We stopped and checked and then cleared the codes and everything was fine for the 600 plus miles to Idaho . On the trip back home both code 404. 405 along with the code 470 were thrown, all at separate times. Once again we stopped, checked the codes and cleared them. There was never a drivability issue or loss of power. Each time we were under a load and going up through the mountains when any of those three codes were thrown. And then a couple days ago it through code 405 again well just driving in normal traffic on flat roads and not pulling anything. This time the code will not clear. Anybody got any idea what the heck is going on. My friend son is just throwing parts at it and I know he’s change the EGR valve at least twice. I told her not to let her son throw parts at it because he’s just wasting time and money if the problem isn’t fixed. Thanks… joe

[rspears]

Joe, this is from a quick Google using 2005 f250 code 404 as the criteria. "P0404 FORD: Code Meaning, Causes, Symptoms, & Tech Notes (With Video)" https://www.engine-codes.com/p0404_ford.html#causes

Sounds like your EGR is hanging open, affecting the EGR flow rate. Hope this helps, or at least gives you a link for mere ideas.

[TooMany2count]

The EGR fairly new, was replaced in the past 3 months

[rspears]

The EGR fairly new, was replaced in the past 3 months

From the little I read it could be the solenoid, the connection or the wiring harness. This is a common problem, it appears, and there are a lot of things posted about it.