Originally Posted by BlackLsCoupe
that could be true. but why isnt it on all of the time. im a mechanic in training. just dont know **** about evap and motors yet
my base had this same issue, put a gas cap on it. didnt come on for a month. then its MPG dropped to 10. spent over 2k tracing nothing. so i dont want to end up there. it ended up being a EVAP canaster leak i couldnt find. found this out after i traded it in on this
are you in GM's ASEP program? if so, your teacher should have the Tech2, ask to borrow it and check for EVAP codes and check in SI [Service Information] for diag checks and codes for the gas cap.. i cant remember which section it is in SI but its there to diag the EVAP/gas cap..
EVAP "Can" is under the car next to the rear suspension torsion link, it has metal wrap-around-strap on one end, with two sensors and a vapor line connected into it..
like the picture below..between the suspension and exhaust pipe..