well my car was running great for a while but it always had this problem during idle that it would sometimes start to rev up from 800-1500 rpms when idling. I talked to my mechanic and he said it was probably a vacum leak. does anyone know how to check it out. i check along the intake and everything seemed like it was fine, maf, tb, intake were all connected correctly and didnt have a leak. What else could it be, where else could i check. I dont really want to take it in a pay big bucks to get it fixed if i can do it. plus the car still runs great

 

A hand held tester like a Mityvac is a good tool to help trace any vacuum leaks in hoses or apparatus.
Your IAC could also be dirty, causing erratic idle.

 

i did the throttle body bypass do you think that could be it? but if i rememebr correctly i think it even did it before then