I've got a 95 non-M. I'm planning on going Megasquirt in the near future but since the motor's only halfway in right now, I'd rather get the blockoffs and put them on before the manifolds get bolted on. How much does the EGR system help with emissions? I live in a GA emissions county so I'll have to pass next July but figured the MS setup could help when that time comes.

 

The absence of the EGR system will probably cause the ECU to throw codes 16 (EGR function sensor), 28 (EGR solenoid valve [vacuum]) and/or 29 (EGR solenoid valve [vent]) however it should not impact the operation of the vehicle.

EGR helps to reduce the NOX (nitrogen oxide) component of exhaust gas, by decreasing peak temperatures during part-throttle cruise. This is pretty much precisely the condition tested during the rolling-road smog check, however you will likely still pass assuming your catalytic converter is in good shape and your mixture is not too lean. Retarding the spark timing slightly may help if you find yourself just over the limit.

 

Can I just weld the bung in the exhaust manifold closed?

I assume I can just cover the holes in the intake manifold for the EGR itself and the exhaust gas tube with a piece of aluminum or something similar. Is that correct? Is there a cheap blockoff kit available?

 

just crimp the egr tube closed.

 

You can do anything to the bung on the exhaust that you want, of course.

Here's a blockoff plate for the intake: Flyin' Miata : Engine conversions : 1.8 conversion : EGR block-off plate (You should be able to fabricate this yourself.)

Also, here's some previous discussion on the matter: http://forum.miata.net/vb/archive/index.php/t-1337.html

 

Can I also remove these two solenoids?

 

If your car is an OBD1 then you can rip out everything associated to emissions. They are gonna sniff check your car and if its tuned right it will pass.

IF they are going to be plugging you in(I assume youre running parallel) and you are afraid of CEL's then you will have to retain all the emissions equipment electronic components.

 

I'm OBD1, it's sniff only. Looks like that FM part is the way to go.

 

Yea, tear that **** out.

The only thing you have to worry about is a visual inspection, but usually a 50 under the table solves that problem.

 

They don't check for emissions equipment except the cat and my car's catted so I'm good to go.