EGR delete
 

Hey,

My EGR tube is open after the blocked tip has fallen off.

Does the intake manifold suck air if the EGR tube is open ?

If I want/need to delete it, I need to delete the sensor too ?

Is this enough ?

https://www.miataturbo.net/attachmen...ine=1388828038

Or I need:

https://www.miataturbo.net/attachmen...ine=1388828038


Thanks ! :party:

You'll need both. They are both open to the intake manifold chamber.

This thread is helpful.

https://www.miataturbo.net/engine-pe...-delete-37239/

Basically, if you're on the stock ECU, you wanna do what's pictured in your first photo, leaving the valve and all related vacuum stuff intact to keep check engine lights from turning on. I'm pretty sure this solved my CELs on the '94 I'm working on, however I haven't driven it much. Some have reported the need to add a valve cover breather filter onto a chopped off EGR pipe, so the EGR valve gets some fresh air.

With MS, chuck it all in the trash.

Fairly certain this is wrong. The lower oval shaped flange from the EGR pipe visibly loops back to the lower port of the EGR valve. When cued by the 1990's Mazda engineer, it opens and allows exhaust into the intake. I could be wrong though. Otherwise you'd have an intake leak through the EGR pipe and exhaust.

Now that I think about it you are correct. You would need the upper (larger) one, but the lower one could be left open assuming the upper is sealed off.

I just left the valve in (disconnected) and blocked off the other hole with a plate.

You need the square, you don't need the diamond. Make sure there is a bead of liquid gasket running between and around the two holes in the square before you apply the plate.

I ran just the top with MS and the rest of the EGR setup in place and drove down from Dallas to San Marcos. Didn't have an issue but I soon removed it and ran the bottom block off plate and yanked the rest EGR system.

Somewhat related question: I'm in the middle of putting a 94-95 1.8 in my 91 and there's a vacuum switching valve on the intake manifold near the throttle body that my 1.6 doesn't have. Am I correct in assuming this is for the EGR and can be removed during an EGR delete?

It actually goes between the FPR and the intake manifold. Yes, you can remove it.

On the 1.6 there is one between the throttle body and intake on the 1.8 it is at the back of the intake where curly described. Both can be removed with MS and set on fire.

I just yanked all that crap on my VVT motor and kind of went ghetto, but clean at the same time. Bought a couple different sized freeze plugs, found some that fit tight and greased with JB Weld.

Cool, thanks!