mystery oil?

[beastman]

Hi guys, I put mystery oil treatment in my oil and gas tank. I was told by many people this stuff is the best. I ran it through a 94 bmw 325i and 94 mustang 6 cyl. Both cars are seeming to run bad. Both run pretty much like crap. It said on the bottle that its poured into oil and gas tank and it cleans everything. Whats going on here? Im kinda pissed off. thanks

[Justin e36]

If it's still in your gas tank, then wait until it burns out and you refill.. then see how the cars are.