Are you deleting the EGR on your Miata or installing a 1.8 in your 1.6 car? Then you need this to cap the fitting on your header or exhaust manifold. Fits 1994-97 and 2001-05 non-Mazdaspeed EGR fittings. Please note that using this part on a car fitted with a 1994-05 stock computer will result in a check engine light.
For 1999-00 fittings and MSM applications, we have an EGR plug.
These year ranges refer to North American vehicles. EGR designs varied in other countries. Please confirm if your manifold has a male fitting (which uses this cap) or a female fitting (which requires our EGR plug instead). It's our understanding that most European cars use male fittings but it's up to you to check.