Some models may have a problem where the Check Engine light illuminates indicating an improperly tightened fuel cap. Due to improperly manufactured threads on the fuel filler pipe, the filler pipe may need to be replaced.
Car Problem Reports
Mazda RX-8 Check Engine Light Due to Improperly Manufactured Threads on Fuel Filler Pipe
Mazda RX-8 Problem
Average Mileage: 43,102 mi (13,500 mi - 72,705 mi)
Visitor, 2007 Mazda RX-8, 13,500 mi
When I go to fill gas tank the filler cap is almost completely loose.
I had the check engine light come on, and they
diagnosed it as gas cap. I had to buy a new gas