once the whole system has been cleaned out, possibly treating your car to some new nozzles, ensure you use only clean, demineralised or distilled water. I use only pure drininking water and this helps no end in keeping the system clean. Good Luck !

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1993 190E 2.0L (Euro.) sold
1991. 500 SEL (Euro.)
1991. 300 CE (Euro.) sold
1993. 500 E (U.S. spec.)