While troubleshooting a hard shift issue, I unplugged a vacuum sensor and voila, car runs great. I don't know what this part is and I hope someone can help. It is MB part # 0025401497. It has two vacuum lines on top and one electrical connector on botttom. The part is near the front of the engine and seems easy to replace.

What is this part and where can I get one (reasonably)?

Thank you in advance.

Jim Coulter
'99 C280, Automatic, Silver
82,000 miles
my first Mercedes

 

From OEMpartsdirect:

Part number 0025401497
Emission system - Emission components - Valve - Changeover
$23.38

Also this:
Emission system - A.i.r. system - Diverter valve
$23.38

 

I will try it.