I actually have an injector tester & cleaner. I bought it from the "mercedes guy" on **************. I will test all my old ones and the new ones I bought when arrived. The car has 150k miles. I will report back my findings

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2001 E55

2001 E320 Sedan

2001 Subaru Legacy

2006 SLK280

2016 Subaru Outback 3.6