A/F Correction

[welaish]

below

https://drive.google.com/file/d/0B6zn_kRV08vAcm5GVFZjWnVUMTg/view?usp=sharing
https://drive.google.com/file/d/0B6zn_kRV08vASDlMVnBpM0d4ZDA/view?usp=sharing
https://drive.google.com/file/d/0B6zn_kRV08vANkM5WHJOVUM2X1E/view?usp=sharing
https://drive.google.com/file/d/0B6zn_kRV08vAQlFyYmpNTHNoQjQ/view?usp=sharing

 

[HolyCrapItsFast]

I would be interested to see what Tk-421 comes up with.

The data shows a leak throughout the driving range but this also could be a very badly scaled MAF because A/F correction often goes in the completely opposite direction that A/F Learned does. Or we could be looking at a bad sensor. I can rule out the O2 sensor because that tracks your wide band almost perfectly. The MAP sensor also seems to correspond well with the MAF sensor, though I did see some wildly negative spikes in the MAP when you are off the throttle. Not sure this is normal since this is the first time I have observed this behavior.

What are the mods on this car and was this tuned recently? Are we looking at stock MAF scaling?

@TK-421, See anything?

 

[TK-421]

I would be interested to see what Tk-421 comes up with.

The data shows a leak throughout the driving range but this also could be a very badly scaled MAF because A/F correction often goes in the completely opposite direction that A/F Learned does. Or we could be looking at a bad sensor. I can rule out the O2 sensor because that tracks your wide band almost perfectly. The MAP sensor also seems to correspond well with the MAF sensor, though I did see some wildly negative spikes in the MAP when you are off the throttle. Not sure this is normal since this is the first time I have observed this behavior.

What are the mods on this car and was this tuned recently? Are we looking at stock MAF scaling?

@TK-421, See anything?

I'll have to get back to you [MENTION=9]HolyCrapItsFast[/MENTION]. I'm currently sitting at Atlanta airport waiting on my flight.

 

[welaish]

[MENTION=9]HolyCrapItsFast[/MENTION] thanks for your reply. :

The car was running fine. Suddenly the huge correction appeared.

Mods:
Turbosmart recirculating BPV
Turbosmart wastegate actuator
Grimspeed EBCS
Crawford AOS
Tomie ELH
Crawford catted DP

As i mentioned on the 3rd post. I cleaned the maf and even tried another one from a friends car.

 

[welaish]

[MENTION=9]HolyCrapItsFast[/MENTION] sorry this is not the stock MAF scalling, the car is Stage 2 Tuned.

 

[HolyCrapItsFast]

Do you have any friends that also have a 2012 that you can temporarily swap sensors with. I would like to rule out a bad maf and map sensor.

If this happened as you describe, it can only be one of three things IMO... A leak, a bad sensor, a bad harness or connector.

The car was fine and suddenly it is not so something happened. I would also do another proper leak test by pressurizing the entire intake system. The dealer or a speed shop should be able to perform this. I also would not rule out a failing fuel system like pump or injector

 

[HolyCrapItsFast]

maybe take a log with injector duty cycle just to see what the injectors are doing.

 

[welaish]

I swapped the MAF sensor same behavior. The car is running amazing not a single knock and AFR in openloop as per the table.

 

[welaish]

I mean other than a AFcorrection on the computer the car is running as normal as before.

 

[HolyCrapItsFast]

Yes because the ECU is compensating by adding as much as 25% more fuel in some areas and well over 10 in most others. This is both good and bad in that it will compensate and make things safe but there will be no real indication that anything is wrong unless you start logging and observe the fuel trims for yourself. The problem comes when you go wide open throttle or any other condition that puts the car into open loop. It is, at this point, where fuel will not be compensated for because the ECU ignores input from the O2 sensor. Your normal AFR will suddenly be dangerously lean.

And this is why I think there is a bad sensor somewhere or a bad connection. In open loop you say the afr is okay.

 

[HolyCrapItsFast]

Try unplugging the O2 sensor and then take a log of normal driving while logging your wide band.

I would like to see what your AFR's are when there is no close loop compensation.

 

[welaish]

[MENTION=9]HolyCrapItsFast[/MENTION] ok will try to do that. Thanks man

 

[welaish]

I have created 1 more long driving log with IDC. I could not reach O2 sensor Plug, I have to lift the car up. will try to do it over the weekend. [MENTION=9]HolyCrapItsFast[/MENTION] [MENTION=4577]TK-421[/MENTION] can you look at it and give your thoughts.

I drove on different load as well the Correction is maximum on 3k rom.

https://drive.google.com/file/d/0B6zn_kRV08vAMGdabVl6WER2YWc/view?usp=sharing
https://drive.google.com/file/d/0B6zn_kRV08vAU2JxYi1EX2NvOWs/view?usp=sharing

 

[welaish]

bump!

 

[HolyCrapItsFast]

I really have no other input until I see what it does without the O2 sensor.

 

[welaish]

Just a quick question it will switch to open loop without the sensor?

 

[HolyCrapItsFast]

Exactly... I want to see what your AFR's are with out the O2 feedback getting in the way. I want to see that throughout the driving range.

 

[Spamby]

I have created 1 more long driving log with IDC. I could not reach O2 sensor Plug, I have to lift the car up. will try to do it over the weekend. [MENTION=9]HolyCrapItsFast[/MENTION] [MENTION=4577]TK-421[/MENTION] can you look at it and give your thoughts.

I drove on different load as well the Correction is maximum on 3k rom.

https://drive.google.com/file/d/0B6zn_kRV08vAMGdabVl6WER2YWc/view?usp=sharing
https://drive.google.com/file/d/0B6zn_kRV08vAU2JxYi1EX2NvOWs/view?usp=sharing

Front O2 sensor should have the connector in the engine bay, left of the intercooler. Blue cable IIRC. You shouldn't need to raise the car to disconnect it.

 

[welaish]

[MENTION=1507]Spamby[/MENTION] will check it.

 

[welaish]

[MENTION=9]HolyCrapItsFast[/MENTION] I managed to remove the O2 sensor and the car becomes very lean between 3k and 3.5k and it idles on 15.8AFR log below:

https://drive.google.com/open?id=0B6zn_kRV08vAU2JxYi1EX2NvOWs&authuser=0