gm code p045 help

[josejuan_602]

Hi I have a 2003 GMC sierra and right now my truck has a misfire when I drive my truck it drives perfectly but when I come to idle it seem like its going to shut off but it goes back to regular idle and this happens everytime I put a code ready nd the only code that appear was p045 some Guy had told me he had the same problem and that he changed the throttle body space gasket and that ended his problem I did it nd my truck its still the same! Any suggestions will b appreciated thank you!!

[ride65]

I believe p045 is a vac. leak in the emissions somewhere. Gas cap? Maybe a bad line in the vapor recovery system?