My MX-5 (pronounced MEE-AH-TAH) was running like crap. Plus, I needed an excuse for my terrible laptimes down at the track. I didn’t really think anything was wrong, I just assumed the car was old since it’d done almost 400,000 km. After all, there was no check engine light lit up on the dash or anything.

Well, it turns out Mazda just didn’t fit a check engine light to my MX-5 at all, and I really did wonder why my engine felt more like a dodgy old malaise-era shitbox than a smooth 80s Japanese powerplant.

It turns out there’s a a simple way to check for diagnostic codes on the MX-5, so I ran the diagnostic and lo and behold, there were problems! I’ve done some work since and I can confirm the car is running much better. Here’s how it’s done.