RepairPal Certified shops can diagnose and repair your 2005 Chevrolet Monte Carlo. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
It sure doesn't sound like it's shifting okay, but rather that it's a seriously delayed shift out of 1st or 2nd. First thing is to check your transmission fluid level (engine running, transmission warmed up, in Park).