check engine light on, failed emissions test, could it be a vacuum leak? or???? on 2004 Buick Rendezvous

2004 buick rendezvous. it's not the gas cap, or pers sensor. would a vacuum leak make it fail emission test? what would a ballpark figure be for cost to fix. Could it be part of the recall??

Asked by for the 2004 Buick Rendezvous
1 answer 2 comments
several things will cause a failure. seek a diag from a good mech that has a smoke mach and good scan tools
Thanks, I'm going to Autozone this morning to do the check and then to the mechanic. Thanks for your reply.
I'm having the same issue with my Buick. Smoke test tomorrow but curious on what was the cause on your vehicle? I've already changed the gas cap, so that's not the problem.