Just got motor rebuilt a few weeks ago. Yesterday the Rpms starting getting really low to a point were it felt like it was gonna stall. Then it starting bogging and buckking pretty bad. Cel came on and it's p0336 (crankshaft sensor) and p1399 (random misfires). I haven't checked the sensor yet but I had coil pack issues with the car before. So I swapped all 4 coil packs with my buddys s and it drove normal with no cel. So I put my coils back in and it ran light crap again with cel. I scanned the cel again and it was only the p0336 this time. So I'm kinda lost right now. Are the coil pack(s) causing the p0336 to come on?

 

Let me make sure I follow: You had a misfire and you swapped coils...the misfire went away. Then you put the old coils back in and the misfire came back. If that is right, then yeah, it's pretty obvious indication that the coils are causing the misfire.

Otherwise, go through the steps in the Misfire Troubleshooting Thread that is in the FAQ/DIY sticky.