I thought I'd play, dumped in a small bottle on 3/4 tank of fuel.
Not sure if it's quieter, no unusual smoke, and as of after my 25 mile drive home tonight, my 1500-1800 noisy injector is quiet. Hmph...
Diesels are such funny motors sometimes..

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K