Any ideas what could be causing this? EGR valve has been removed and blanked. It only happens after a longish (30 min) drive and once stopped and idling. I haven't been able to plug it in to a computer but just wondered if anyone had an idea of what it could be before I pay out to have someone look at it. Thanks in advance.

Forgot to say, 03 Warrior K74 4d56 etc.

Have you checked all the vacuum pipes on the back of the rocker cover...I know if two are the n wrong you will get an eml at idle ( guessing you did block EGR vacuum pipe?)

Thanks for your response, Ronnie. I will check them tomorrow. EGR vac pipe is blocked. It's strange. If I turn off ignition for maybe 10 seconds it then turns off the eml when I restart it. No performance issues. Thanks again.

read the code no point in getting the crystal ball out