I probably already know the answer to this questions BUT I will ask anyway. I have seen and done myself tricks to reduce the air fuel mixture by using potentiometers to intercept certain computer signals. Is there any way to cheaply increase the ait fuel mixture not via a stand alone or piggyback? I know I am being cheap to not spend 1k on a tuner and tune but thought I would ask. I know I wont get an much out of this kind of trick but thought i would ask.

 

okay...what are you trying to do? increase or decrease? a cheap way to do it would be...ebay power chips, which are pretty much resistors that make the car dump some extra fuel to make more power right?

 

in theory it sounds good but i really dont think it will work very well at all...some signals vary greatly and trying to use something like this would prolly just stick it either lean all the time or rich all the time...ther wouldnt be much of a happy median with this. also you would most likely throw codes all day long bro if not throw the car into limpmode. I really wouldnt risk damage to sensors or engine just to cheap out like this...i can promise that you will end up spending much more in the long run.

 

I do want to increase it, was just saying I have done it the other way on older vehicles to increase milage.

Are there any fuel controllers that someone with some knowledge could tune themselves and not get themselves into too much trouble? Say like the Apexi AFC Neo Air Fuel Controller?

 

None will adjust your timing...

 

perhaps look into the aem fic...in the long run its cheaper than most piggy backs and is fairly easy to learn.

pnp harness is around 300 and fic is around 400...neo is cheaper and much more simple to use but thats what kinda makes it bad...its too simple, meaning it only controls one sensor i think. the fic controls 02, maf, cam, crank sensors. by being able to do this you can avoid getting a cel if tuned properly. neo is very limited in what it can do before you overstep the ecu's threshold of what it will accept.

 

also, whatever you do, the ECU monitors the a/f ratios in the exhaust header and it will see that the a/f's are changing and make adjustments to correct whatever you do to it.

 

the ECU adjustments aren't as harsh on the 05-06 ECU's. On the 07+, it's a freakin' brainchild... ugh turbo woes...

 

I was looking into the FIC but along with tuner and dyno charges it started to get a bit high for what I wanted out of it. Is there some material out there for some self learning on the FIC?

 

If you have never ever tuned a car before, then I would suggest looking up a few sticky's on it and if you just can't grasp the concept without actually doing it, then definitely bring it to a tuner. Boost ain't cheap any way you look at it.

 

this will help a bit

https://www.scionlife.com/forums/sho...d.php?t=153354

 

Awesome link Crush thank you. I think I am ready to take the plunge after I take my car into the dealership to fix the vacuum flucutation I am having now which apears to be internal to the engine.

 

let us know how that turns out..