1990-97 Cam Sensor O-Ring

Just buy this gasket. It works, it's easy to replace, and gives you a peace of mind from not having to deal with the "Devil Hose" if you have the 1.8 engine.

What is the "Devil Hose", you ask??

The Cam Angle Sensor gasket is pretty infamous on the NA Miatas, it's basically guaranteed for the OEM gasket to fail which will cause an oil leak. The oil leak is usually very small, but on the 1.8 engines the CAS is placed right above a small rubber coolant hose that goes behind the engine, stuffed between the engine and the firewall. When the gasket fails, the oil starts to leak directly onto this hose. After a while the oil starts to deteriorate the hose, which will cause the hose to burst open, spraying pressurized coolant everywhere. I learned this the hard way.

This particular coolant hose has been named the "Devil Hose" by the Miata community. It has earned this name because it can cause catastrophic damage, and it can be a ROYAL pain to replace. There is very little room behind the engine to access the hose. You can remove the entire intake to give you better access, but it can still be a struggle to get off without proper tools.

Make sure you properly mark how your CAS was mounted before you take it off. I just drew a line with a Sharpie on the CAS and the mounting bracket so I could line it up perfectly afterwards.