I bought a 1996 Miata last year, already inspected and ready to get tags. This year, inspection time is here and they can find the emissions plug to test the emissions to pass it ! The mechanic said he looked under the dash and hood and couldn't locate it. I take it to a mechanic and he says I should sell it. It runs perfect. what is the plug that's missing? Really expensive, the wiring it in hard ? I don't understand ! Anyone got any ideas on this ?!
Thanks so much, BetsyJane

 

Apparently, they changed from obd1 to Obd2 in 95, Yours may be a 96 model that still uses obd1.

Here is a discussion on the issue, I hope it helps you sort out your problem. Print it out and take it to the mechanics. (Be nice to them, no one knows everything and mechanics don't like to be caught with a gap in their knowledge.;-)

96 Miata - OBD I or II?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

 

I had a similar problem with my pre-owned '96 Miata. After failing inspection due to the "missing" OBD-2 connector, I was sent to one of two "special" State inspection facilities many miles from where I lived for a followup inspection. There, a technician combed through the underside of the dashboard and under the hood searching for the connector. After several phone calls, he resorted to a manual emission (probe) check to "pass" the vehicle inspection process. He promised that the missing connector would be noted in the computer system and I would not have the problem again.

Years later, when I brought the car in for re-inspection, the same bureaucratic SNAFU occurred. This time I determined to get to the bottom of the issue. After an intensive Google search, I found several postings on this problem. I followed the suggestions and found the answer.

The original bracket for the OBD connector on this car was flimsy. After one or two uses, the bracket breaks, leaving the connector dangling from the connecting wires. Owners and/or mechanics, shove the connector and wires up into the tangle of other wires under the dashboard to conceal and "secure" the connector. Sometimes, a careful search can discover the hidden connector. (In my case, the careful search by the State technician and by myself, still couldn't find the missing connector.) However, sometimes - especially when a radio or other entertainment device has been added, or the stock radio has been changed out - the loose connector gets shoved under the radio during installation.

To explore this possibility, I removed the radio/CD player and carefully searched the crevices below. Sure enough, there it was, tucked in among the many other wires. After reinstalling the radio, I revisited the inspection station; the car "passed" without further incident.