did it loose power while sea foam was in the tank, or a couple of tanks later??? That's probably all the problem was, when i ran a kerosene to diesel mix in my truck (bout 30K/70D) It ran alot quieter but with less power, b/c kerosene ignites before diesel does so that little bit of power you could've gotten from it wasn't used, but it did clean out your cylinders and your injectors... got better milage out of it with a couple of tanks of the concoction.
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-Old ride-82 Luv diesel 5spd with some upgrades
-Past rides-82 Sierra, 78 Coupe De'Ville, 91 2dr Blazer, 86 RX7, 86 Porsche 944T (rear-ended and totaled)
-Curr. rides- 1970 Ford LTD 4dr, 390 4Bbl, 2nd owner! With a few Extras

00' Civic beater...