97 4runner to 99+ 4runner airbox/MAF conversion

[toytech76]

I just converted my 97 runners airbox/MAF to the newer 99-02 style. In case anyone deosnt know, the 96-98 MAF steups are more restrictive and very expesive to replace. (about $600 from the dealer)




You alos need to repin the MAF connector to work with the newer MAF. I was able to with the help of MTL4runner. The stock wire colors while looking at the back of the connector left to right are, Black/white stripe, brown/black stripe, yellow/green stripe, red/white stripe, white/blue stripe.



The modified pin setup is now, brown/black, yellow/red, red/white, black/white, white/blue.



While I had the airbox out, I also remove the airtube insde the fenderwell and removed the 90 deg off the plate the airbox hooks into.










Removing the 90 and the airtube is reported to give you better airflow, better throttle response and slightly better MPG's. It also is reported to give you more rear wheel HP than a K&N cold air setup for supercharged motors. Go to gadgetonline.com for more in depth details about that. Its actually one of the steps involved when installing the TRD 7th injector. I also upgraded my headlights to the 99-02 styla and will be installing my HID coversion in a couple weeks when my kit arrives. I will be doing a writeup on that when its done. Hope this helps anyone attempting this conversion!

[MTL_4runner]

Sweet, nice pics too.
I'm sure this will be popular when people see how easy it is.

Link from the MAF pinout thread:
http://www.ultimateyota.com/index.ph...01.0;topicseen

[YotaFun]

I will try this when I have the cash to get the 99+ setup.
Now question, do you have to get a 99+ airbox or is the 96-98 easily modified?

[toytech76]

you need the 99+ airbox plus the newer sensor. I got a used airbox for $50 from a tacoma at a wrecking yard. The runner boxes and tacoma boxes are the same. You will also need a new MAF sensor if it doesnt come with it. They are about $130 new from the dealer. Total you shouldnt spend more than about $200. Not bad considering the price of a new MAF for the 96-98 setup

[MTL_4runner]

You should get the MAF and the airbox at the junkyard together and expect to spend around $40-100 for both depending on where you live. If you need a new 99-02 MAF I have seen them go on ebay for around $30 too.

[arjan]

I can't believe it's that simple.
Interesting how Toyota stuck to the same sensors, but messed with the wiring order.

[toytech76]

They are 2 different sensors. Thays why you want to upgrade to the newer one

[arjan]

Yes but the sensor characteristics of the actual electronic sensor must be the same, else it wouldn't work.

[MTL_4runner]

Yes but the sensor characteristics of the actual electronic sensor must be the same, else it wouldn't work.

The principle is the same on almost any vehicle that uses a hot wire MAF sensor instead of a MAP sensor or an AFM. You could probably figure out how to wire any vehicle's MAF sensor (whether it be a Chevy or a Range Rover or a Toyota, etc) in there provided the voltage outputs were more or less the same as the donor vehicle.

[arjan]

But doesn't the hotwire system really measure airspeed (airflow over the sensor)?
That would mean if the maf housing is less restrictive (ie larger diameter) the airspeed would be lower
The efi computer would register less air, and that would royally bugger up your air/fuel ratio I would think.

Unless the computer 'learns' the characteristics from the results at the oxygen sensor, then it wouldn't matter. I don't know into that much detail how the fuel curves are setup.