The great EGR (running rough, idle, cold start) mystery finally solved. Input pls
Hi guys and girls, I have studied tested and dreamed Mazda triBute egr running faults and testing.

I hope this saves you time and money as there are so many misleading posts and threads as our mazdas do not conform to usual methods.

Tribute 2002 with erratic idle, found leaks and changed the hoses, idles perfect now.
Common leaks include hoses and gaskets.
Now have stumbling and lack of power under acceleration.
Whated a vid saying a healthy egr will stuble idle if vacuume is applied to egr, mine completely dies?
Another vid told me to take out egr and clean it out, it was already clean?
I watched another and it suggested making another egr gasket without the hole. Cutting of the flow. If engine runs cool then your egr is stuffed. Test drove and the misfire kangerooing went but the engine seriously lacked power and felt totally off but smoother than before.
Next was to clean out carbon deposits from the intakes in the engine. When the ports clog the fault code says emissions and the system is imbalanced with ports clogged at different stages, if all ports are blocked then engine will run smooth but will fail emissions test.
All over the web people show the simple job of cleaning the ports on other cars but our Mazdas are nothing like other cars and the ports are not in the head or accessible at all.

Preforming the simple tests in this order will get your car diagnosed fixed or bring you here to clogged port hell.

This is where I am at, so advanced advisors help needed pls.

Other clues are, the suction in to the sensor right before the egr is way stronger then after the sensor.
Adding suction to the egr makes the engine totally cut out?
Blocking the egr with a whole less gasket in the egr make the running under powered but no jerking at acceleration.

 

I don't have a Tribute but a 98 protege. There is a EGR boost sensor (as if the EGR would boost something! Ha!) located at the firewall , passenger side. From there is a vacuum tube going to the backside of the intake manifold. That tube sits on a nipple and that nipple gets clogged with deposits. If it is clogged that sensor doesn't get the vacuum signal....I opened that nipple with a piece of wire and replaced the vacuum tubing because the rubber was hardened.

On the protege the EGR ports are at the mouth of the intake manifold , 6 and 12 o'clock.

I wouldn't be surprised if the the Tribute had the same set- up.

 

Are the egr ports inside the Throttle body or manifold ?
How far should you be able to push the wire into the nipple behind the manifold ?

Thanks

 

In the Protege the EGR ports are at the mouth of the intake manifold , 6 and 12 o'clock.
About 3" will do for sure. I cut a bicycle spoke diagonally to create a point and about 3" back from the point I bent it into a handle.

 

Tore everything apart again last night , 12 o'clock port was pretty clear , 6 o,clock port must be plugged somewhere inside the manifold . Sprayed carb cleaner in side port and did not drain. There are a few freeze plugs on the manifold in the EGR port path , trying to figure out if it is worth it to pull these out and clear the pathway ?

 

If the EGR valve is closed it may keep the carb cleaner from running into the exhaust manifold.
Do it again with the EGR valve removed.

 

Should have mentioned , EGR valve was off.

 

O.k.
I have never removed a freeze plug. Therefore I can't comment on that.
You could try blowing compressed air through the tube.