How to Clean your EGR Valve on your Mazdaspeed 3/6 or CX-7 to fix the P0401 CEL Code

Got a P0401? This is for you. Your EGR is stuck. Colder weather will create this more often too. light will go off after 4 driving cycles, but return if still stuck. This is for people who want to retain the EGR. You can block it off and clear the CEL through AccessPort if you want. I performed this cleaning 6 years ago. A couple years later I got the code again. I read about Chevron Techron Complete Fuel System Cleaner (big bottle) from an auto parts store helped many. Well I went and used it on a tank. 200 miles later, I think 8 driving cycles, and light went off and stayed off for a year. Repeated annually. SO this may be an option if not totally caked. Eventually I got an Accessport and blocked the EGR.

I got a P0401 CEL at 51K miles on my 2007 Speed 3 the other day after 2 or 3 days of slow starts, where it would crank a while before firing up. Guy at Advanced who read the code said EGR was clogged, a $430 part from the dealer. Having owned a Protege 5, I knew what a stuck EGR was like, and how it can be cleaned, but no how-to posted yet for the Speed3 apparently. I read a few threads online, and here especially, so I am posting here first to share. This is how I did it. Feel free to do it differently if you feel like it. This is probably not the only way to do it. It is just how I did it. Don't like it? Well, sorry I guess. A 10 and 8mm deep and shallow socket, pliers, a 22mm wrench, flat blade and Philips screwdrivers, Brake Parts cleaner, and some coolant will be needed. Oh,and a person with skinny fingers.

1st, it is not that hard to do if you know a little bit on working on our cars already.

1st, where is the EGR. It is here:



Now what to do. To start, remove your OEM TMIC, battery and battery box. Also remove your turbo inlet pipe. loosen the top on the coolant overflow tank. Put a rag in the turbo.
The EGR is the silver thing with the black plastic on top. The pipe with 2 bolts coming out to the left of it is the EGR pipe.


There is a hose coming out of the back of the EGR, held on with a clamp. Pull the clamp back, disconnect the hose from the EGR, and let the coolant drain. You will lose a quart or so, the overflow will be empty.

Remove the 2 bolts holding the EGR on, and pull it out. Here is the EGR with the gasket on it. You cannot see it, but there is carbon inside, Nasty, but comes out easy.


Now go up to the front to the throttle body. You may make a mess if you have not already removed the coolant lines from the throttle body like I did. If you did not, do it now.

Remove the throttle body by taking out the 4 bolts:


Now use that 22mm wrench, loosen the bolt holding the front part of the EGR pipe now visible:

remove the pipe:


Admire the nice pile of carbon in front of the pipe.



Feel free to blow compressed air through the pipe while it is removed. If clogged, use a coat hanger or something, and get out as much as you can. You might need to take it to a mechanic to get it dipped in parts cleaner if you do not have it.

Skipped pics, but remove the 4 screws holding the plastic top of the EGR valve. Don't strip or break them. They are as a strong as Dollar Tree trash bags.

There is a plunger. It is stuck. spray with brake cleaner on the holes, until clean, Scrape out carbon if needed.

Then reinstall everything.
The end.

 

Wouldn't it be easier to just unplug the egr sence it robs you of power on these motors?
Only downfall is the cel light.

 

That is a drawback. This is for people who want a working EGR System.