2005MSMiata

Hi All,

First, I am super new to this site, to tuning my car, to Miatas, all of it. I got the car kind of as a project during the quarantine, and I am wanting to re-work it a bit and have bought a bunch of parts to do so. One challenge I have is that I have never registered the car (as in got a valid license plate), so I need to do that. I will need to be able to pass emissions testing, but I also want to run a megasquirt tuning thing (whatever the heck you call them) and am upgrading my turbo, exhaust, etc. So, the question I have is, if I need to run the megasquirt, hoew can I pass emissions testing? I know they won't be ab;e to plug into the port under the dash, so I don't know how it works.

I am just now getting started on the project, and am trying to do some research before I get too far down the road with everything.

Thanks.

The car prior to any mods.

original engine bay

WigglingWaffles

Either find a way to register and plate it in a non-inspection state or swap back to stock for every time you need one is what i understand.

Megasquirt is not emissions compliant. Not sure if its true or anecdote, but i heard certain costal states can crush your car outright or give unaffordable penalties if you get caught.

Z_WAAAAAZ

What state are you in?

CA emissions testing for your car will fail you for anything aside from a stock ECU. Your '05 is tested on an OBDII scanner which the Megasquirt won't communicate with.

Most people set their car back to stock (and drive it that way for a couple hundred miles to set the smog "monitors" required so the ECU will pass the smog machine's OBDII test) every two years here before smog to pass inspection. Then revert back to Megasquirt/turbo/etc following the smog check.

When I was still in automotive school, a couple of my classmates "had a guy" for their cars but I'm not familiar with how that works.

Fun story: a buddy of mine got pulled over in his turbo/vvt swapped '91. The officer said the car had to be sent to the state referee by a certain date so they could verify he removed all the illegal aftermarket parts and replaced all the required emissions componentry. This dude's kinda stubborn and he had thrown away or donated all of the stock powertrain bits off the car. So he bought another stock '91 Miata, got it smogged with the stock powertrain, promptly tore everything out and put it in his other '91 that had been ref'd, took the car and got it signed off by the referee, and put his vvt turbo motor/megasquirt/etc into the new Miata. Now he has another turbo Miata and his old one has been converted into a stock daily driver.

Moral of the story, keep all your OEM parts and emissions equipment somewhere and try not to get pulled over in California!