It is possible that you need to replace the Cabin Air Filter on your vehicle. Manufacturer recommends to change the filter every 2 years or 30,000 miles. Filter cost is around $25~ $30. Find the instructions here; http://bit.ly/cngawe
RepairPal Certified shops can diagnose and repair your 1997 Honda CR-V. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.