Growing up in California with all of its emissions regulations, an EGR valve has become a fact of life, and it is a huge factor in our bi-annual smog checks. However, after pulling my engine ('91 Convertible, manual tranny, California car) and tearing everything off the "block," I couldn't help but notice that there is no EGR valve. Mazdatrix also doesn't list an EGR valve for the S5.

Can someone confirm that the S5 was not fitted with an EGR valve from the factory, specifically for a California car? And if an EGR valve wasn't equipped, does anyone know why or how Mazda got away with that?

Thanks!