I am 2nd owner of '93 245 with 134K. The engine control temperature sensor was replace by PO at 110K. I got the car at 119K and the engine check light has come on frequently and has been traced as a 123 code...engine control temp sensor. We finally replaced it last week, and the stupid engine check light has come on three times since, all reading with a 123 code....AAARRGGGH! What gives with this puppy? It seems to do it when there is a temperature change and the car seems to stumble a little and run rich, but runs fine at highway speeds.

Any thoughts from the bricksters?
John

i changed out a temp sensor today on a 1989 240 the sensor that i removed was a bosch the plastic was black in color at least one of the numbers on it was 850,the sensor that i installed was also bosch,but the plastic was blue, i didnt check the number,i pulled it out of a good running 86 740.the 240 is now showing a 123 code and if i rev it fast before it warms up,the check engine light comes on and stays on until i reset the code.does any one know if the black and the blue innerchange? on the ignition side of the test i am showing a 224 code?

they do not interchange and using the wrong sensor will cause a code. the part # for the correct sensor on both of your cars is#1346030