Ok well i am posting this here because u guys respond quicker and i need help like yesterday. Ok well i had been reading all the Seafoam things here and i was like hey if its good enough for a GT its good enough for me so i tried it on my 6 feeding it through the Brake boster line. I followed all instructions and fed it little by little and then like let the car shut itself off. Let it sit for 15 minutes then drove it around and it smoked and was fine stopped after a few minutes. And i noticed it running a lot better. Ok well here is where my problem starts i figured if it worked great for my 6 that i keep maintained always using synthetic oil and using injector cleaners and crap then it should do miracles on my mothers 96 Jeep Grand Cherokee with a 4.0 liter I6 which is not nearly as maintained as mine. I did the same thing, fed it through the B/B line and then when i went to feed enough through so the engine shuts itself off, the car started to idle real low, and sound like old V8's before they shut off, then started pouring smoke through the engine under the intake manifold and i hooked up the line to the Brake boster quick and shut off the car, when i took the keys the engine started to diesel and was still like trying to shut off but wouldnt and the keys werent even in it, and i waiting like finally 3-5 secs after the keys where out it shut off. I am afraid to start it now, do you think i did some serious damage? Or is this normal, because my car did not do this but did it do this for any of you guys?