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Discussion Starter · #1 ·
Hi Guys,

Was wondering if anyone could help me out with what may be going on with my car. Just tuned it last wednesday and DAM has not stayed at 1.0. Please read below:

I just recently purchased an accessport and have been on the stage 1 ots map for about a week now. I have noticed that my DAM parameter keeps fluctuating pretty frequently with it now sitting at 0.5. My AFRs look good, but TD Boost Error seems to be consistently off (I do live in Denver though). The car seems to run fine and I definitely dont hear any pinging but am still concerned. I have a .csv file with one of my recent WOT pulls in 4th gear from 2500 RPM if someone wouldn't mind checking it out. Could low quality fuel be the culprit? should i try the HWG map? Any help you can provide would be greatly appreciated.

Vehicle info:
2015 Subaru WRX Limited
55k miles
Invidia Gemini R400 cat back exhaust is the only mod
little to no oil consumption over 3k miles
 

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You are not running the stage 1+ correct?
 

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Sure, post your log.

Also -- what do you fuel trims look like?
 

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Discussion Starter · #5 ·
I am having trouble attaching a .csv file and also .xlsx. Do you know what file types I can attach?

As far as fuel trims, I am not sure. Pretty new to the tuning world. Worked as an automotive Engineer in MI though so I do have a pretty good background of knowledge. Is that something that can be monitored with the AP?
 

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Yes.

COBB said:
A/F Learning 1

This monitor shows a percentage correction for fueling. Positive numbers indicate that fuel is being added. Negative numbers indicate that fuel is being removed. The closer to zero the better, but generally, the acceptable range would be +/- 8%.

Negative corrections beyond 8% mean the ECU is pulling lots of fuel. This would most likely be due to a leak in the intake tract. Other potential issues could be a bad MAF sensor, failing o2 sensor, or you may have a map flashed that is not designed for your intake or injectors.

Positive corrections beyond 8% mean the ECU is adding lots of fuel. There are several potential culprits in this situation. A failing fuel pump, dirty fuel injectors, or bad MAF or o2 sensors would all be good starting points to address the problem. As always, having parts installed not designed to work with the map you are running could also cause high positive fuel trims.

MAF and o2 sensors are typically on their way out after ~100k miles. If yours are still original, and you have mileage beyond 100k, replacing these sensors would be recommended. Definitely replace the front o2 if engine or turbo damage has ever occurred. When it comes to these critical sensors, always use OEM parts from a Subaru dealer or a re-seller of genuine Subaru OEM parts.
Fuel trims are MAF based. You will want to log AF Learning 1 alongside MAF.
 

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Discussion Starter · #7 ·
Sounds good. Thanks for the info. I will make sure to add those two parameters and take another log tonight and find a way to post it
 

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Discussion Starter · #8 ·
Yes.



Fuel trims are MAF based. You will want to log AF Learning 1 alongside MAF.
After looking at the log I took the other day on the WOT pull from 2500rpm. I was logging AF Learning 1. It stayed below +8% the entire time. What is the MAF parameter I should be tracking? MAF corr? If so do you know what ranges are acceptable?
 

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Logging AFLearning during a WOT pull will give you 0% because the ECU is in open loop fueling.

What you need to do is log the AF Learning parameter while driving around normally, against RPM and Mass Airflow. This will show us the learned fuel trims in each of the "buckets" of closed loop fueling.

Back in the day, this was easier as you could pull all of the trims at once with OpenECU, but times have changed...
 
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