What MAF is this?

94SS_Canada · Post by **94SS_Canada** » Thu Oct 16, 2008 11:27 pm

Is this the one that can handle more boost on a T leg? while on stock ECU?

PhyrraM · Post by **PhyrraM** » Fri Oct 17, 2008 3:17 am

That's the JECS "plastic" AFM. You cannot use this on the stock ECU with the stock injectors without some sort of engine management.

I do have a therory. That MAF w/JDM "grey" 440cc injectors and a stock ECU should make a very good low buck combo. THEORY!! I make no claims other than to say I THINK it should work well.

94SS_Canada · Post by **94SS_Canada** » Fri Oct 17, 2008 4:17 am

What about With my Setup, This thing plugs right in and its also has that extra pin my stock harness wiring has in it, I thought this would make a good combo with my 440cc injectors, Dosent kill to try right?

Funny though i found this on a 91 N/A legacy...

94SS_Canada · Post by **94SS_Canada** » Fri Oct 17, 2008 4:18 am

Oh ya, with supporting mods, is this an "Upgrade" like can it meter more air better than stock?

PhyrraM · Post by **PhyrraM** » Fri Oct 17, 2008 4:49 am

Yes it will flow more than the Hitachi aluminum AFM.

It will throw a code when used with a stock SS ECU. I believe either Josh or Doug has the workaround for it.

94SS_Canada · Post by **94SS_Canada** » Fri Oct 17, 2008 4:59 am

Will This code cause the fuel to be cut? But simply a code?

PhyrraM · Post by **PhyrraM** » Fri Oct 17, 2008 5:10 am

Not sure, but if I was programming an ECU for a turbo car and I had to decide how to handle a MAF related code I think I might put it in limp mode. And make it run safely rich.

94SS_Canada · Post by **94SS_Canada** » Fri Oct 17, 2008 7:29 am

SO your telling most likely this will put the ECU in limp mode, i understand and all but why would subaru make our stock MAF(5 pin) and our harness which is a 6pin but plugs into the 5 pin be able to directly connect and make up for that lost wire on the 6 pin connector, seems odd too me, ill see what this does since the car isnt even running yet...

Post by **Legacy777** » Fri Oct 17, 2008 5:22 pm

The extra pin is not needed. I believe at one time it may have been an extra ground or something.

Any way you slice and dice it, putting the JECS MAF on with any combination of injectors, (stock, 440's, etc) without some form or aftermarket engine management will not produce an ideal setup.

Yes you may be able to get close and match injectors, etc. But without something to adjust AFR's/tuning, you may be ok at idle and part throttle, but be running lean at the top end, or vice versa.

As for disabling the CEL, I believe you just have to snip the one wire that identifies the difference between the two MAFs, JECS & Hitachi.

Adam West · Post by **Adam West** » Fri Oct 17, 2008 6:53 pm

There's a post on this from Doug - Reddevil. Search it. I have one of these ready to go but it needs a wire taped and grounded (grey?) before installing. I can attest that this will f-up your tune if you don't do this but don't quote me on the how-to it's a Doug thing. PM him, he's very helpful. BTW, I have ppt6 wired in but not running now. I wouldn't consider running the MAF without it - just like the smarter folks above this post are saying. Cheers, AW

PS. why this is good is that it doesn't top out at certain voltage level which the Hitachi MAF does - 5 volts I think. Again, I'm NOT the expert but I know some (and still get it all wrong)...

94SS_Canada · Post by **94SS_Canada** » Fri Oct 17, 2008 6:54 pm

How come i pulled this off a N/A legacy, what makes that ECU diffrent than ours? Why come that legacy use this MAF and not ours, i trust your guys information it just makes no sense that the N/A legacy can make use of this and not ours...

I was thinking of getting that chip for our ECUs anyways so that should solve any problems i might run into.

Say i did have proper assistance with this MAF what does it allow me to do my stock one cant?

Adam West · Post by **Adam West** » Fri Oct 17, 2008 7:12 pm

This would allow you to run more boost before fuel cut... i.e. what I just wrote about 5 volts...Again search Reddevil's posts for details...

Can you post the link to the chip you mention?

PhyrraM · Post by **PhyrraM** » Fri Oct 17, 2008 7:29 pm

The N/A Legacies had them because Subaru switched ECU suppliers around that time. Turbos used the 'old' Hitachi ECUs and Other cars used the 'new' JECS ECUs.

It is a larger AFM, even on a lesser car, as a cost saving measure. The older tech Hitachi needed an AFM closer to the actual usage (HP) of the car. The newer tech JECS obtained the same resolution even if 'the whole thing' wasn't used. So as a cost saving measure, Subaru can put one AFM part number in many different cars.

RJ93SS · Post by **RJ93SS** » Fri Oct 17, 2008 7:34 pm

this is the link adam http://bbs.legacycentral.org/viewtopic.php?t=37582

Adam West · Post by **Adam West** » Fri Oct 17, 2008 7:50 pm

Wow! That does change things...

94SS_Canada · Post by **94SS_Canada** » Fri Oct 17, 2008 7:59 pm

PhyrraM wrote:The N/A Legacies had them because Subaru switched ECU suppliers around that time. Turbos used the 'old' Hitachi ECUs and Other cars used the 'new' JECS ECUs.

It is a larger AFM, even on a lesser car, as a cost saving measure. The older tech Hitachi needed an AFM closer to the actual usage (HP) of the car. The newer tech JECS obtained the same resolution even if 'the whole thing' wasn't used. So as a cost saving measure, Subaru can put one AFM part number in many different cars.

SO what are you saying here, that i wouldnt be able to use this on stock injectors but with upgraded injectors and everything else i can make use of this? Or do i have to get the chip?

skid542 · Post by **skid542** » Fri Oct 17, 2008 8:04 pm

If you want to run this MAF, regardless of your setup of injectors/turbo/etc., you WILL need some form of EM to control the signal the ECU sees or eliminate the ECU completely and go standalone.

This MAF is a tool that only works in conjunction with other tools.

94SS_Canada · Post by **94SS_Canada** » Fri Oct 17, 2008 8:07 pm

skid542 wrote:If you want to run this MAF, regardless of your setup of injectors/turbo/etc., you WILL need some form of EM to control the signal the ECU sees or eliminate the ECU completely and go standalone.

This MAF is a tool that only works in conjunction with other tools.

Okay, Well i guess ill have it when i get that chip!

Adam West · Post by **Adam West** » Fri Oct 17, 2008 8:29 pm

Sorry, I had the user name wrong for your searching - Douglas Vincent is the perp...

http://bbs.legacycentral.org/viewtopic. ... highlight=

Post by **Legacy777** » Mon Oct 20, 2008 5:37 pm

Also to add, when the Legacy was introduced in 1990. The manual trans cars used the Hitachi based ECU's, while the auto trans cars used the JECS based ECU's.

I don't think it's an age issue with the ECU's, and I'm not even sure it's a programming issue, because I believe the overseas legacies/liberties used the JECS MAF and ECU.

94SS_Canada · Post by **94SS_Canada** » Tue Oct 21, 2008 3:17 am

Legacy777 wrote:Also to add, when the Legacy was introduced in 1990. The manual trans cars used the Hitachi based ECU's, while the auto trans cars used the JECS based ECU's.

I don't think it's an age issue with the ECU's, and I'm not even sure it's a programming issue, because I believe the overseas legacies/liberties used the JECS MAF and ECU.

Yap, pulled it off a 91 auto

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What MAF is this?

What MAF is this?