Maft Pro and Wideband

[2_TonedMKIII]

I have already done a few searches and haven't found the exact setup/ answer I'm looking for. My question is;

Does the ECU still need to see an "o2" signal or can I just wire my out put from the wideband to the Maft pro?

I don't plan on running an o2 sensor.

Im running Auto Meters new wideband.

And clearly the Maft pro.

Thanks,
Kyle

 

[90T04]

Yes the ECU still needs its o2 sensor input. The MAFT-Pro only changes the tune of the engine in open loop anyway. At part throttle, the ECU should be in closed loop, maintaining air fuel ratio via input from the stock o2 sensor.

 

[dumbo]

Yes the ECU still needs its o2 sensor input. The MAFT-Pro only changes the tune of the engine in open loop anyway. At part throttle, the ECU should be in closed loop, maintaining air fuel ratio via input from the stock o2 sensor.

wrong...
the maft pro has part throttle afr tracking as well at WOT afr tracking.
disconnect the stock o2 and it puts the computer in open loop 100% of the time, and then wire the wb into the maft pro and it tries to run it.

i'm kinda fighting mine though, but im getting there.

 

[whitesupra]

Hi guys i am knew to this forum..I have a 91 supra i have mod..i have blitz nur spec exhaust system..intake,Hks boost controller,and lexus amf..My question is could i still used the lexus amf? or do i have to change my original amf? I also have 550cc injector and walbro fuel pump install..My engine is now running soooo rough at idle..please help me to fix my problem.. this is all i have for mod

fludyne radiator
550cc injector
lexus maf
lexus afm
walbro fuel pump 255 l/h
hks boost controller
turbo elbow
3'' downpipe
apexi blow off valve

 

[NewWestSupras]

Get a wideband so you can monitor your a/f's. Could be a vacuum leak causing a lean condition perhaps. Makes 'em run like crap. Check all the hoses, they can leak from the damndest places.

 

[hvyman]

i was under the impression that the ecu still needed input from the o2 sensor so it goes into closed loop. if im correct on this correct me if im not, the wb feature is just a feature like a aem wb with out the gauge. and if oyu unplug it the car is never going to go into closed loop and be in warm up enrichment mode the entire time.

??

 

[MA70Snowman]

hvyman, you understand the basic concept well enough. however when you throw the MAFT pro in there, it changes the equation entirely. The Maft pro has a TON of features and honestly it comes down to the individual user on how exactly they want to employ it. and one of the main decisions is O2 or no O2.

1. O2
The maft pro takes over when ur at WOT and funtions as a basic tuning device. however when at partial throttle or cruise, the Computer goes back into closed loop and is no longer under control of the MAFT Pro

2. No O2
Disconnecting the STOCK O2 sensor forces the ECU into Open loop 100% of the time. Thus allowing you to utilize more features on the MAFT pro such as Partial Throttle Tracking. Essentially allowing you to tune your cruise and low load points, or gentle accelerations. If you were to have your Stock O2 plugged in, The ECU and the MAFT pro would be fighting each other to get to the 14.2 range (or whatever your ideal is)

Something alot of people need to remember. is the MAFT pro is not a novice tuning device. I thought it was at first but spent the better part of a month buried in forums, before I even attempted tuning. The above is a VERY BASIC concept of MAFT pro operations. For more indepth knowledge i HIGHLY recommend going to their website and reading the general and the Supra section

Supra section-
http://www.fullthrottletech.com/forumdisplay.php?f=14

 

[90T04]

i'm kinda fighting mine though

exactly...


the MAFT pro isn't a standalone, and you shouldn't expect it to perform like one.

 

[90T04]

i was under the impression that the ecu still needed input from the o2 sensor so it goes into closed loop. if im correct on this correct me if im not, the wb feature is just a feature like a aem wb with out the gauge. and if oyu unplug it the car is never going to go into closed loop and be in warm up enrichment mode the entire time.

??

You are correct. The Toyota ECU needs an input from the stock O2 sensor to operate correctly. Without it, the stock ECU will be always in error mode, probably throwing a code 21 and a CEL. I don't understand why these people want to run the engine with the stock O2 sensor unplugged. What a ghetto way of doing things. ANY piggyback is only going to give you control in open loop.

 

[suprafredde]

Never mind the fuel part since that is fixable.

But what about timing maps, if the ecu is in error mode does it still run on its normal timing?

A friend told me that ignition control with the maft is only 10 degree retard and thats is.

suprafredde

 

[Fozbo]

2_TonedMKIII:

Yes, you can run the car without an O2 sensor as long as you have the maft-pro with the wideband. It will throw your ECU into open loop at all times and cause your CEL to be permanently lit, but it will allow the maft-pro to have much more control over the fuel delivery and tuning of the engine. Personally, I would suggest still running an O2 sensor while you get the Maft-pro up and running.

I am running this exact way right now; Maft-pro with speed density, boost control, and my O2 sensor unplugged. Before, I was running with the O2 sensor still plugged in. During part throttle cruising and driving, I was too lean and kept trying to correct it with the maft-pro. The ECU kept pulling fuel out to get back to what it thought was right. After some research, I unplugged the O2 sensor and it solved the problem.

 

[CPT Furious]

If you guys look into some of the possible solutions for the uplugged stock O2 sensor, all you really need is a 1/4 to 1/2 watt 1kohm resistor plugged into the stock harness and it'll keep the CEL from illuminating.

Like some of the others here, I was timid about doing this at first, but now I've done it and haven't look back. The Pro is a highly capable device and yes it's not a standalone, but it does a helluva lot of stuff other piggybacks don't do.

For those of us that can't afford or don't want to pay for the full blown standalones out there or pay for their setup and tuning, this works wonderfully. The customer support is also top notch.

BigAaron has some posts about installing the resistor to keep the CEL from coming on. Essentially, it makes the ECU think the O2 sensor is still there, but it is being fed information from the MAFT Pro.

 

[dumbo]

yup it does a lot. i run with stock o2 unplugged as well cause my car also was running lean at idle before i did. but i dont get a solid lit cel, but i do have a couple codes. when you got tunerpro running it feels like a standalone.

supra fredd if you hook up the timing control (couple resistors needed) you can adjust from +5 to -10 degrees at given RPM and LOAD. and monitoring you gotta open the box and cut a resistor. damn awesome!

 

[hvyman]

wow great info.

so dumbo your saying that the maft pro can control timing to some degree? which would make it not a piggy back but not a standalone at the same time?

 

[dumbo]

wow great info.

so dumbo your saying that the maft pro can control timing to some degree? which would make it not a piggy back but not a standalone at the same time?

It can control timing to a point as well as monitoring its, i have it wired up but have all my values to '0' haven't played with it yet.
Timing Control

monitoring is a bit difference but very nice.

and its still a piggy back because it and your eng rely on the ECU..but its a damn good piggy back..but i am having some afr inconsistencies

 

[MA70Snowman]

It can control timing to a point as well as monitoring its, i have it wired up but have all my values to '0' haven't played with it yet.
Timing Control

monitoring is a bit difference but very nice.

and its still a piggy back because it and your eng rely on the ECU..but its a damn good piggy back..but i am having some afr inconsistencies

That is true.. any device that relies on the Stock ECU is a piggy back. some just rely more or less on it. The MAFT PRO is about as far as you can go w/o going stand alone. the control you have over all the aspects is just amazing. Especially now that they've given us timing control and monitoring. I haven't played w/ timing control yet myself but am getting ready to.