99Trooper

[Iowegen]

Hello I have an EGR valve problem. I am geting code PO401 PO405. I have replaced the valve and sprayed cleaner down the tube. Now I didnt use a whole can nor did I plug the exhaust port. My check engine light remaine on with these codes. I have been told it could be my EGR valve wiring harness because the description behind the code as low sensor circuit. Can anyone shed some light on this issue? I also have the check light on my TOD system on. I have told that the cause is most likely one or both of the sensors on the transfer case. Any ideas on this issue as well? I have 145k on the Trooper it runs great. Thanks