Ok so i have been driving my 2001 wrangler for the last 3 months and has run pretty good other than the grow out bearings are going on it.. I just drive it on a 600 mike trip this past weekend and drive awesome no issues other than the throwout bearing noise. Well Sunday I got home and the jeep sat a hour or so and I went back out and jumped in it to leave for a few well a new noise started and it was a loud tapping noise that got louder when u have it has when u let off it wasn't really there. So Monday I drive it to a shop and they told me it was a rod knock and my motor was in its way out. So I took it for another opinion and they can definitly hear something but thy day it may be a lifter noise.. Anyway they gave me a can if this carbon engine cleaner I guess it was and I was told to out it in my crank case Sony took the can and added it and let it run 10 minutes with the idle at 1250 rpm and then u changed my oil well I looked behind the jeep and there was really black liquid that was coming out of the tailpipe while I was letting it run with that additive in there.i can go in buy I will make this shorter. I drove it around today and it runs horrible now, the noise is still there and now it feels really tough and boggish I was shifting in to 3 rd and before it came out of second it felt and acted like the truck was gonna shut down. What could this be? Any help would be appreciated. Thanks.