So my truck has been acting strange the last few weeks. At idle it's can be a bit rough. Also when driving at around 50mph at around 1200 rpm it is a little bit jerky not really bad just a little bit. So today I got the p0405 code . I am pretty sure that I replaced the egr valve less then a year ago. Any thoughts guys

 

Try disconnecting the plug at the EGR and see if there is a difference in how it runs.

 

I will try that tomorrow morning

 

My understanding is that the valve will default in the closed position when the engine is shut down (off), which is where you want it when you pull the connector from the valve. My thinking is that if she runs normal again after disconnect, that should help to further ascertain the culprit being the EGR valve itself. But maybe some of the more savvy diesel heads here might chime in and add to this.