My check engine light came on when starting my car yesterday morning at -4 F. I retrieved the code and it was code 5 for the EGR inoperative. The car is my 1994 E320 wagon. I've read the clear code procedure but my questioin is would very cold weather cause this or was it ready to fail anyway? Could it be ice clogging the EGR?

__________________
dtf
1994 E320 Wagon (Died @ 308,669 miles)
1995 E300 Diesel (228,000)
1999 E300 Turbodiesel ( died @ 255,000)
2006 Toyota Tundra SR5 AC 4X4 (115,000 miles) rusted frame - sold to chop shop
2011 Audi A4 Avant (165,000 miles) Seized engine - donated to Salvation Army
BMW 330 xi 6 speed manual (175,034 miles)
2014 E350 4Matic Wagon 128,000 miles
2018 Dodge Ram 21,000 miles

Not familiar with your car/engine but, wait & see if it does it again.
If you have a vacuum operated EGR, yes it may have had some accumulated moisture that froze in the line.
I remember years ago Chrysler had a terrible time with moisture freezing in the line to the MAP sensor.
When they re-located the sensor to the inside of the vehicles, the problem was solved.
Worst time of the year for moisture related problems is when the temperature bounces cold/mild.

__________________
2007 C 230 Sport.