Just a question

https://www.google.com/search?q=Where+is+obd2+port+on2002+mazda&biw=1362&bih=650&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjb68P25JrQAhWC14MKHUfwDxgQsAQIMg#tbm=isch&q=How+to+install+a+egr+valve+on+a+2002+Mazda+Protege

hope this helps

Make sure the EGR ports aren't clogged with carbon. It can completely clog ports. EGR shouldn't be open at IDLE, but it will open upon accelerating.

-Scott

I believe it is located directly underneath the throttle body intake.
https://www.google.com/search?biw=1536&bih=710&tbm=isch&sa=1&q=99+mazda+protege+egr+locaton&oq=99+mazda+protege+egr+locaton&gs_l=img.12...21014.28237.0.31287.18.14.1.2.2.0.139.1095.13j1.14.0....0...1c.1.64.img..2.7.396...0j0i30j0i8i30j0i24.6332pmbkKZI#imgrc=jJ5CIOyc_k3dbM%3A

https://www.google.com/search?biw=1536&bih=710&tbm=isch&sa=1&q=99+mazda+protege+egr+locaton&oq=99+mazda+protege+egr+locaton&gs_l=img.12...21014.28237.0.31287.18.14.1.2.2.0.139.1095.13j1.14.0....0...1c.1.64.img..2.7.396...0j0i30j0i8i30j0i24.6332pmbkKZI#imgrc=jJ5CIOyc_k3dbM%3A

P0660 Intake Manifold Tuning Valve Control Circuit/Open.. Although you may want to first look at a new EGR Valve - particularly in Mazda.
PS: Your local auto parts store can also define OBD II Codes.
Best regards
Ck

yes a hose not connected will cause a malfuncition light but the egr can also get plugged

could anyone please help me with this problem that i have with my 2001 mazda protege es 2.0. i have a bad catalyst converter and im waiting for the converter to come in, but before the guys that are fixing on my car relize that i need a converter they put a egr valve and a o2 senor and when the car idle some time it will just die one me. could someone tell me what is going on.

This link is to a "How To Replace an EGR Valve" video. While he is doing this on a Ford F150 pickup, the tips he gives you should translate over to your Mazda easily, especially as he talks about the stickers under the hood designed to tell you where your EGR valve and solenoid is located. Give it try...I think it will work for you.

http://www.wonderhowto.com/how-to/video/how-to-replace-an-egr-valve-226125_2/

it has a digatal egr valve remove the egr valve and lean it with top engine cleaner from GM, with a tooth brush, then test the stepper motor with an ohm meter if it mesures more than 6 ohms replace it.

first take the egr valve off then get some carb cleaner spray it into the egr valve ports let sit 30-60min then take a small flat head clean any carbon left over in it. then check the vaccume lines to it they to might be plugged you can take a small wire or push pin and stick it in the ports to unplug it.