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.Google+
Car Problem Reports
Mazda Miata MX-5 Check Engine Light Due to Improperly Manufactured Threads on Fuel Filler Pipe
Mazda Miata MX-5 Problem
Average Mileage: 35,528 mi (8,444 mi - 145,000 mi)
Visitor, 2006 Mazda Miata MX-5, 29,605 mi
check engine light comes on. Dealer Service shows problems with fuel filler pipe but this vin# not included in recall. Why?
Visitor, 2012 Mazda Miata MX-5, 16,500 mi
CEL comes on
Gas cap comes loose
Visitor, 2006 Mazda Miata MX-5, 9,550 mi
got code p0442 and replaced fuel cap with new redesigned mazda one. light stayed off for 100 mile and came on again. cap was loose. dealer will not fix.
Visitor, 2012 Mazda Miata MX-5, 16,000 mi
Check engine light came on. The code read by the service center pointed to the fuel filler cap. It was replaced and the problem went away.
Visitor, 2010 Mazda Miata MX-5, 21,941 mi
engine light comes on and stays on, the fuel filler cap is loose, I tighten it and in a few days it comes loose again all on its own.
Visitor, 2007 Mazda Miata MX-5, 38,000 mi
Starting when I bought this car used with 37000 miles on it I get a check engine light the code set is a loose gas cap and has now occurred 3 times in the last 9000 miles. I know that the cap has been reinstalled properly after refueling and I have to bring the car to my mechanic to reset the engine light, the cap is loose when the light comes on.
Visitor, 2006 Mazda Miata MX-5, 61,500 mi
Check engine light on
Visitor, 2006 Mazda Miata MX-5, 24,030 mi
Repeated check engine lights after fueling vehicle and tighening gas cap.
Visitor, 2010 Mazda Miata MX-5, 8,444 mi
Taken the car in to the dealership 3xs. They continue to maintain that the light is on because I am not "tightening the gas cap enough"! I KNOW how to tighten a gas cap!! Today I was humiliated while the service consultant explained that "if" I am telling them the truth, they will do me a "favor" by replacing the gas cap, because it is clearly the owner's mistake and not theirs! Grrrrrr
Visitor, 1999 Mazda Miata MX-5, 145,000 mi
I have not fixed the problem, but every time I fill up the gas tank, the check engine light comes on. Once the fuel level drops below 1/4 tank it goes away.