a few weeks ago my buddy was drive my 00 civic and he was went from 3rd into 2nd instead of 4th in high Rpms. My car started running rough. It idles just fine but I'm driving in 1st at about half acceleration yu can hear a rattle and once I let off the gas the car dies. Any ideas what it could be? Does it sound like a spun road or rod bearing?

 

Mechanical over revving an engine is always dangerous to valvetrain. Do a compression test, and if there is a low cylinder, do a valve adjustment on it first to see if you get lucky... if not, you gotta pull the head before you eat the valve and destroy the entire engine.