Check engine light came on at 600 miles. Took it to the dealer and the code was a p3400 code, cylinder deactivation fault. The dealership replaced both solenoids, part #PYFA-12-360A, found metal in OCV valves. When we got the car back I changed the oil, cut the oil filter open and found large metal shavings. At about 1300 miles the same check engine light came on. Back to the dealership with the same code. Now Mazda says to replace the head.