Do all MBZ cars have a mono valve? I have a 1990 190E 2.6 (wife's car) and the center air vents sometimes put out hot air...as if the heater is turned on when it isn't. Also, I am in the market for an EGR valve for the car. Does anybody know of good pricing? It seems like the going rate is around 196.00. Thanks. Tom 90 560SEC