I had to have it replaced about a month ago. The original one died without any warning at all. I took the car to a local reputable independent Mercedes shop and they replaced it with one from a salvage yard. The number on the original unit is 004 545 44 32 and on the replacement part it's 006 545 76 32. They visually look the same and I was told by the shop tech that they were interchangeable. Can any of the professionals here confirm this for me? My engine is knocking under even moderate acceleration and I think it's gotten worse since the module was replaced.

Thanks,

Gary