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View Full Version : MAF Enhancer Adjustment?



scubasteve1043
09-08-2008, 03:47 PM
I have an 02 ford focus with the 2.0L SOHC and I used the instructions from water4gas to make the maf enhancer and it is working. I am just not really sure what the best setting for it is. I can stall out the car so I know that its working right, I also had it turned down some and I heard the pinging so I turned it back up quickly. I just want to make sure that I'm not hurting the motor but I want it to make a difference also.

Keith's Garage
09-08-2008, 11:54 PM
The best way to adjust the MAF is using a scan tool. You want to watch the LTFT. Adjust The MAF so that the LTFT is around -10%. Unless you have a scan tool it is hard to say if the MAF is adjusted correctly.

Mindcrime13
09-09-2008, 01:11 PM
the maf it could work in the first minutes but once the car goes in closed loop is useless, an o2 enhancer would work better,

thats what i read , im not 100% on this info, but you should check it out

good luck!

scubasteve1043
09-10-2008, 09:48 AM
Well the maf adjustment works the whole time I'm driving, I can be going down the highway and turn it down and feel the car pulling back and turn it back up and its like hittin the gas. I can set it pretty high and if I get on it the car will hesitate unless I turn it all the way up so I don't know that it would really help any if I have it all the way up, I'm guessing it would use the same amount of fuel or more.

Keith's Garage
09-10-2008, 02:36 PM
The MAF is always being used. It does not matter what loop the vehicle is in. The ECU uses info from the MAF, O2, ECT and other sensors to determine how much fuel the vehicle needs. The MAF is a demand sensor, which means that when the MAF demands something it usually gets it.

hydrotinkerer
09-12-2008, 02:17 PM
The MAF is a demand sensor I agree, but using just a MAF adjustment the ECM/PCM has the ability to learn that adjustment and change back to ideal air/fuel ratio. The o2 sensor is the last sensor the vehicle looks at for fuel control. This is for the big three, imports have different protocols. All you have to look at is what the sensor does: MAF, mass airflow sensor- it measures incoming air. Oxygen sensor: It measures the amount of excess air in the exhaust. Both are needed for fuel control, but telling a lie to both, The o2 will believe you longer and more completely.

Keith's Garage
09-12-2008, 10:39 PM
You are totally right about that. The ECM is going to believe an enhanced O2 value longer than an enhanced MAF/ MAP value. This is mostly because the O2 is not used as often as the other sensors. I think that enhancing both sensors is your best bet to get the best gains possible.

Cadillac
09-14-2008, 04:37 AM
I can only speak from what I have seen with my car.

When messing with a MAF sensor I have gotten the code P0504, idle higher then expected. Normally I would suspect a vacuum leak. Tested all the lines. I have no MAP sensor so I know it is not detecting a differance. I cleaned the IAC valve a couple months ago when I cleaned the breather system. The only time this code has ever flipped is when the MAF enhancer is set leaner (way leaner then I have it set normally) and it idles for a bit. It kind has me thinking that it can see the differance in the air coming through in the amount of voltage going to the IAC valve. It is using less then expected voltage to maintain the normal idle at 450 rpms. I am unsure how the computer actually reacts to this code. Seemed kind of fishy to me.

Still even with the MAF sensor set very tame I have seen constitent 5-7 MPG increases. No codes other then when I make it interupt the a signifigant amount more. I know not all cars are the same though.

focus_hho
09-15-2008, 12:08 PM
Cadillac,

When you say MAF sensor set very "tame", do you know how much voltage drop you are changing MAF by? I can monitor the biased MAF signal I'm sending to ECM (via DVM and OBD scan tool) with my enhancer. If I drop it by 0.2 VDC or much greater it runs rough, and I will eventually get P0171 code, system too lean.

Cadillac
09-15-2008, 04:26 PM
Yes, it is a cadillac. All cadillacs since 82' (except cimmaron, catera and allante/all from different companies) have the ability for diagnosis or system monitering from the dash with a couple buttons.

It seems to flip when 0.2-0.3 volts are distorted.