on my 1996 W202 I needed to retard the ignition by about 3 degrees after having fitted a Turbocharger.

After lots of reading and research and (annoying and boring lots of people) help from others...

(Ashman, 2phast, MBenznl, Mark300SL, willy @ Mosselman)

I managed to locate the infamous part!

location: left wing (fender to you usa peeps) under the washer bottle, prise of lid of ECU and ye shall find!!!


Cover off:




my old plug (024 545 06 28)



pull it out!



old and new part



side by side:



underneath



new one in!





REFERENCE THREAD