NB Miata project – Performance modifications after six months
In my last post I covered my experiences looking for and purchasing my current project car, an NB Miata. I also covered preventative maintenance work to get the car up to a known reliable state so that I could move forward with other mods and really enjoying the car.
This post covers NB Miata performance mods that I have done to my car during the first six months of ownership. I explain what I did, why I did it, and what my experiences were with various different mods.
Full exhaust system
When I first got my Miata it had an engine code related to the post-cat O2 sensor. My car was originally a California car so it originally had two cat system. A pre-cat built into the exhaust manifold downpipe, and a secondary cat downstream from there. O2 sensors are placed before and after the pre-cat. The secondary O2 sensor is just for emissions, so it didn’t impact the use of the car. I still wanted to fix it, but wasn’t in a rush.