EGR problems after replacing everything.
I am looking for further suggestions on an EGR problem. I first replaced the Vacuum lines, then the Switch Over Valve, Next I found the article in the DIY section on cleaning the EGR tube with a speedometer cable. I had the shop do that when I was in for an oil change. Lastly I replaced the EGR valve over the weekend and I still am getting the EGR problem. The shop says possible wire harness problem when I called this morning for further suggestions but it isnt random like that, each time the light has come on its when I have pressed the brake to stop for a light. It sounds to me like they are now guessing and guessing can get expensive. Especially when you guess a wiring harness. Suggestions please!
1986 190E 186K (For Sale)
(Maroon, Tan leather)
1996 C280 Sport 208K
(Brilliant Silver, Black Leather)
2002 CLK430 Sport 45K
(Brilliant Silver, Gray Leather , Birdseye Maple)