RepairPal Certified shops can diagnose and repair your 1997 Volkswagen Jetta. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Look for vacume hose that could be split or disconnected. From that point it could be caused by various faulty sensors, wiring problem, or a mechanical problem. Driving with a lean condition for extended period could leed to more problems.