Just bought a used 2006 F250 only 85k miles and in great condition. shortly after purchase check engine light came on. Ran a code and got the EGR P0402 code. Replaced the EGR valve, next day, light came back on same code. Reset the code then hooked up my camper, light never came on while pulling the camper. as soon as I disconnected, Bam.. lights back on, cleared the code, hooked back up to return home, no light. 10 mins after disconnecting camper, light is back. I pulled the EGR valve and it's clean as a whistle. Was told using a Ford part versus a OEM would most likely fix the issue.. Engine runs great, no smoke in exhaust, plenty of fluid in reserve, getting 17MPG in city.. Any help would be greatly appreciated. I'm ready to just pull the light!!!

Thank You!

 

That code does not identify the actual valve as the culprit. It only points you to a failure in that circuit. You then go through a diagnostic sequence to find the problem.

 

thanks Kultulz.. I guess I'm more puzzled by the fact that I don't get any indications or the check engine light while I'm pulling my camper but as soon as I unhitch the light comes on within 10 mins. Was hoping somebody might have had the same issue and would share.