C280 switch-over valve
 

I recently got the Check Engine light on my C280 and took it in to the shop I usually go to and had it read. He didnt give me the code but said it was common for the switch-over valve to cause the EGR valve error and that he would reccomend changing that first, if the CE light came on after replacing the switch-over valve then the EGR valve would be replaced. Does this sound like the correct way to approch it? Also, since I'm starting to do a little more of the DIY work, is the switch over valve something I can do on my own?

Thanks

I doubt it is a bad SOV.
However , it is possible..
More likely it is a plugged egr pipe to the intake [common prop on 104 eng]
There is an article on it in the DIY section and the Search Archives.

An easy test is to apply vac to the egr [ hand pump/mighty mac/etc] while at idle. Eng should run rough w/vac---smooth out as vac is released.
A SOV test is to look for vac at the line to the SOV and the line from the SOV to the EGR.
Common prob in this area would be the plastic line feeding the SOV [ under front plastic eng. panel] becomes brittle and crack...
[ thus, no vac to SOV]

202's also crack the vacum block on the r/h fenderwell area under the big plastic module cover.


Joe