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Ok.........i was asked make a how to on how to do this mod. But first here is a quick explaination of what this mod if for and what it does.

REASON FOR DOING THE EGR MOD:

the Mazda 6s from the factory has a few flaws that may be small and some that can even lead to detrimental damage to the car itself. some of these flaws and/or shortcomings can usually but not always be fixed. But of course the manufactureer wont do it.

Anyway, the design of the Mazda 6s EGR system puts the tube of the EGR directly in the middle of the intake tract. Thats bad business. Basically it blocks the airflow to the cylinders. This compounded with a decently bad design of an Intake Manifold causes 2 issues.

1. one of the 2 cylinder banks will run significantly leaner than the other. How significant are we talking here?
--it has been documented that there is about a 5%-7% difference in fuel trims between the front and rear banks.

******now on a stock motor it probably wont hurt it in the long run. but most of us owners tend to enjoy modding our rides and getting more power. and if this is left stock it could cause engine failure when dealing with power adders such as turbos, superchargers, and nitrous. again 5-7% may not sound like a lot. but that could be the difference of you keeping your 12.2 AFR in one bank......and leaning out to 13.0AFR+ in the other. then boom******

2. it blocks some airflow all together. restricted airflow=power lost

*****drive about 50mph.......stick your hand out the window. feel the pressure on your hand. you get my point*****


HOW-TO:

**TOOLS NEEDED**

-8mm & 10mm sockets with accompanied rachet.
-corresponding 6" or more extension
-8mm rachet wrench(i'll explain why later)
-5/16" socket (i have an Injen CAI with hose clamps, size may vary, per intake)
-newpaper/paper towel/towel (either of the 3 will suffice)
-a hacksaw/dremel with cutting bit/ air powered wiz wheel(either of the 3 will suffice granted you have an air compressor the 3rd would be the fastest)
-pliers(needle nosed/snub nosed)
-flat tip screwdriver

****sounds like a lot but its really not****

TERMS:

EGR- exhaust gas recirculation
IM- intake manifold
TB- throttle body
AI- air intake


PROCEDURE:

1. disconnect the neg. side of the battery 10mm (ensure that its away from the terminal and wont accidentally touch it)

2. look on the TB.........on the side closest to the firewall there is a plug with a lil red clip on it. Pull it up with your fingernail. and remove that plug from the TB.

3. disconnect the AI from the TB using the clamp closest to the TB. NOTE-actual nut size on clamp may vary from intake to intake.

****if you have a CAI there may be another Nut to loosen down by where the air filter goes into the fender(its a damper/mounting nut****

4. remove the engine cover (3 nuts)


5. remove the 3 EGR valve mounting bolts

***the bolt furthest to the right can be a PITA if using a ratchet. it can be done but i suggest using a 8mm rachet wrench***

6. remove 3 vacumm hoses from rear of IM.

***this is where the pliers and flat tip screwdriver come in handy, use them. do not try and just yank them off, where as you could snap off the nipple on the IM. the one furthest to the right can just be pulled off***

7. remove the 2 connector plugs on the front of the IM

***the other is about 6" directly to the right of this one***

8. remove 8 IM mounting bolts

***NOTE- these bolts will not come out of the IM fully. they are locked inside of it for the most part. do not attempt to remove them***

9. remove IM from engine and EGR valve. once you start picking up the IM off the motor STOP! there is one More hose under the TB you must take off. Just look under the TB and you'll see it. there are also 2 coolant lines on the TB that need to be removed. if you havent done the TB coolant Bypass, now would be a good time to do it.

***once IM is removed, besure to place the IM upside down once removed to keep dirt from getting on the seals. and place a towel or cover material of choice over it to keep debris from getting in the runners. also be sure to cover the ports on the motor as well***

***NOTE- the IM does not have to fully come out of the engine bay to do this. but it make it easier to mask the lower runners on the engine as well as keep the debris you're cutting from getting in there. remember you're are cutting metal, you wont see where all the bits and peices go. but rest assured you dont want it in you're motor....thats for sure!***

10. look at your EGR valve that is now exposed. take note that there is a point to where the tube increases in size. that point is the point you must worry about. if you cut too close to that point the EGR valve will then become 2 pieces. NOT GOOD. you must cut about a thickness of 3-4 quarters before the ridge of the high point


here's a hand drawn version of what you have to do:

***once cut you have now performed the EGR Mod.

11. Put everything back together in the reverse order you took it apart. VOILA! modified/optimized EGR valve.

TORQUE SPECS:


INTAKE MANIFOLD TIGHTENING SEQUENCE:


SECONDARY RUNNERS TIGHTENING SEQUENCE(for shits and giggles..doesnt need to be touched during this mod)





ADVANTAGES OF THIS MOD:

1. increased airflow to the cylinders.
2. more even air distribution.
3. possibly better Gas mileage.
4. getting a head start on having a safer motor for power adders down the road.
5. a happier motor.

TOTAL TIME:

approx. 30-40mins

****if doing the TB coolant bypass at the same time add another 15-20mins on it, but if you do the TB coolant Bypass, its safer to do on a cool engine****


I HOPE THIS HELPS ANYONE WHOM WAS CLUELESS ABOUT THIS MOD. hopefully it'll get pinned!
 

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Thanks, The Great NY!

I was going to be doing this mod either today or tomorrow before my dyno/tune day next Saturday. I pretty much knew how to get to it but your illustrations showing what size sockets I need to use will save me some time from fumbling around.

Paul
 

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good write up there. I just might do this today and the TB coolant bypass if I can figure that one out too. anyone have a link to the TB coolant bypass or if there is a how-to on that?
 

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good write up there. I just might do this today and the TB coolant bypass if I can figure that one out too. anyone have a link to the TB coolant bypass or if there is a how-to on that?[/b]
Here's the link, but I'm afraid it does'nt have any pics:

http://www.mazda6tech.com/index.php?option...3&Itemid=49

And thanks so much for the great write-up NY! Ima definitely gonna have to do this one sometime. Worth a sticky!!!
 

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Damn it i just did my plugs and pvc last nite and I was thinking about doing this mod :cursing: . oh well cars are like legos all ways taking them apart...good write up
 

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Yay! this how to was essential! thanks!
 

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Discussion Starter #13
good write up there. I just might do this today and the TB coolant bypass if I can figure that one out too. anyone have a link to the TB coolant bypass or if there is a how-to on that?[/b]

all u need for this is i believe a hose splicer to connect the 2 hoses to each other. maybe 2 proper size hose clamps. it'll leak some coolant but nuthing major. u could use a red plastic cup to catch the fluid
 

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Does anyone know what the torque specs are for the bolts holding down the intake manifold, the EGR valve, and the throttle body (if I end up removing the throttle body)? I just want to make sure it is torqued properly without over/under tightening.

I used to remember the torque specs for the throttle body but forgot.

Paul
 

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I believe I found the torque specs for the intake manifold, thanks to a message Fly757 left in a previous post. Here is a direct quote pulled from that topic:

-A torque wrench is always recomended for things like the intake manifold. You could get away with doing it by hand, but then you're taking some risks.
The upper intake manifold bolt pattern is as follows:

7 1 3 5
8 4 2 6

Torque 72-106 in-lbs. Work slowly and progressively, and in the correct order.[/b]
Now I just need to dig up the specs for the EGR valve and the TB. I'll post them if I can find them.

Paul
 

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I'm in the process of doing mine now. That third hose under the TB is a pain in the ass to remove, I was unsuccessful removing it since it was stuck on the IM so well. Also, don't forget to take a vacuum hose to the EGR valve when finished to suck up any metal shavings/dust that may accrue in what's left of the tube prior to reassembling. I used a dremel cutting wheel on mine and it left some shavings and dust in the egr valve, nothing a vacuum couldn't handle. ;)
 

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Discussion Starter #17
I'm in the process of doing mine now. That third hose under the TB is a pain in the ass to remove, I was unsuccessful removing it since it was stuck on the IM so well. Also, don't forget to take a vacuum hose to the EGR valve when finished to suck up any metal shavings/dust that may accrue in what's left of the tube prior to reassembling. I used a dremel cutting wheel on mine and it left some shavings and dust in the egr valve, nothing a vacuum couldn't handle. ;)[/b]

hey bro. i just added all the TQ specs for everything on top of the motor.

its in my first post just right after step #11. just click to enlarge. hope that helps!
 

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I made it sticky...
 

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Discussion Starter #20
Seriously, this How-To is reminiscent of quality Mazda6tech articles.[/b]
thank you kind sir

I made it sticky...[/b]

appreciate it bro. this should stop the random WTF is the egr mod questions that pop up from time to time.

yeeyah baby, my 1st sticky, lol! :nana: :drive:
 
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