You need to obtain some testing by a qualified, trained technician who is familiar with these vehicles and has proper tooling and reference material to do so.
www.repairpal.com/repair-shops
Follow that address link to find a shop near you that can help.
RepairPal Certified shops can diagnose and repair your 2003 Mazda Protege5. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.