Japan’s transport ministry inspected the headquarters of Honda Motor Co. in Tokyo on Monday after the company and other automakers admitted to carrying out improper tests for vehicle certifications required for mass production. The ministry inspected Toyota Motor Corp., Yamaha Motor Co. and Suzuki Motor Corp. last week and will commence a probe into Mazda Motor Corp. soon after the automakers said safety tests were not conducted in line with government specifications. After the inspections, the ministry will decide whether to impose administrative punishments to prevent a recurrence and determ…