After taking the rubber tube going to the throtte body off, I noticed a few drops of oil in the throttle body, like it was sucking it up the intake tube. What is this from? Is it serious? What can I check?

 

Its from the pcv system. Its to relieve excess pressure from the head and crankcase. It goes back into the intake as vapor and when the car cools, it turns back to oil. If its a small amount, nothing to worry about. If you like it to stop, search catch can

 

what does the catch can do anyway?

 

catches anything that comes thru the line. most often oil or water condensation. its so that the bypass doesnt get all over your engine or on the ground.

 

they should've put them in from factory lol

 

they made the vapor reroute into the engine to be burned. better for emissions and it doesnt require the owner to empty it every so often.

 

^ burned off is better for emissions. If you route the line to the exhaust, no oil in the intake and its still burnt off

it slows down the breather system so the oil vapor turns back to a liquid and pools at the bottom of the can. These ebay cans are empty and dont do crap, if you add in some steel wool, it works better. A real can has chambers that slow the air down