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Discussion Starter #1
2016 WRX premium
44,892 miles
A/T
.375 DAM
-2.81 feedback knock
-4.22 fine knock learn
Any idea what can be causing this? Stock map and stock everything except catback exhaust.
327565
 

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Please post the values for the following parameters:
AF Learning 1 A
AF Learning 1 B
AF Learning 1 C
AF Learning 1 D

These are learned values and so you don't have to crank the engine or even drive. Just record the numbers. AF Learning 1 D should be 0 if this is an OTS Cobb map.
 

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Discussion Starter #3
Please post the values for the following parameters:
AF Learning 1 A
AF Learning 1 B
AF Learning 1 C
AF Learning 1 D

These are learned values and so you don't have to crank the engine or even drive. Just record the numbers. AF Learning 1 D should be 0 if this is an OTS Cobb map.
There’s an update, I had to drive home from work sorry I wasn’t available! But here they are. Nothing feels off in the car.
327588
327589
 

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That DAM is exceptionally low. This is a big issue. The DAM was initially designed as an "octane modifier" that allowed the ECU to dial in a certain amount of global timing retardation to counter any problems with low octane fuel.

What fuel do you have in the car?

Your Fuel Trims look "normal" so I don't suspect a gross vac leak.
 

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Discussion Starter #5
That DAM is exceptionally low. This is a big issue. The DAM was initially designed as an "octane modifier" that allowed the ECU to dial in a certain amount of global timing retardation to counter any problems with low octane fuel.

What fuel do you have in the car?

Your Fuel Trims look "normal" so I don't suspect a gross vac leak.
I’m running the highest we can get in California, 91 octane. Do you suggest I switch to E85?
 

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I’m running the highest we can get in California, 91 octane. Do you suggest I switch to E85?
That would require custom mapping and hardware, so no.

But it is possible that you have an especially bad tank of gas. How much is left in your tank?
 

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Discussion Starter #7
That would require custom mapping and hardware, so no.

But it is possible that you have an especially bad tank of gas. How much is left in your tank?
Nope I always pump shell, well actually maybe! I always pump at the same shell but the other day I pumped by a shell by my job, I have about half a tank. Also when coming to complete stops my RPMS drop heavily, like from 1.5k to 500 they just drop rapidly on the low end.
 

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I don’t think it’s a bad tank of gas, this has been happening for at least 3 trips to the gas station ( roughly 3 weeks) I read it could just be bad gas and to drive it off but it’s still going on. That’s why I’m here now asking to see if it could be anything else I just have no idea
 

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I don’t think it’s a bad tank of gas, this has been happening for at least 3 trips to the gas station ( roughly 3 weeks) I read it could just be bad gas and to drive it off but it’s still going on. That’s why I’m here now asking to see if it could be anything else I just have no idea
And I was also suggesting getting the e85 kit for my car not just going and pumping, just in case you thought I was an idiot lol
 

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And I was also suggesting getting the e85 kit for my car not just going and pumping, just in case you thought I was an idiot lol
Something is wrong. Slapping new parts on the car should not be a priority.

Now comes the rabbit hole. The DAM activates due to specific logic with input from the knock sensor. The exact logic is a bit opaque, but it's assumed that Subaru programmed the control logic to be very predictive and when it believes timing needs to be pulled on a global scale.

One thing to check first and before you replacing anything else is spark -- pull the plugs and make sure that they are in good condition. A plug with a chipped insulator (for example) is knock prone and can cause the ECU to pull timing. While you have the plugs out, it's a good idea to check the compression and leakdown in each cylinder just to rule out internal engine troubles. While you are rooting around in the engine bay, check for any metal shroud/heat shield that might be clanging against the engine block. This can be interpreted as knock by the ECU and cause havoc in the control logic. Then find your knock sensor and ensure that it's properly secured to the block.

I really doubt it's fueling since your fuel trims look good, but your pump COULD have difficulty supplying fuel at higher duty cycles. Are you certain you haven't seen a CEL for misfires?
 

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Also, find out what load values that FLKC is occurring.
 

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Discussion Starter #12
Something is wrong. Slapping new parts on the car should not be a priority.

Now comes the rabbit hole. The DAM activates due to specific logic with input from the knock sensor. The exact logic is a bit opaque, but it's assumed that Subaru programmed the control logic to be very predictive and when it believes timing needs to be pulled on a global scale.

One thing to check first and before you replacing anything else is spark -- pull the plugs and make sure that they are in good condition. A plug with a chipped insulator (for example) is knock prone and can cause the ECU to pull timing. While you have the plugs out, it's a good idea to check the compression and leakdown in each cylinder just to rule out internal engine troubles. While you are rooting around in the engine bay, check for any metal shroud/heat shield that might be clanging against the engine block. This can be interpreted as knock by the ECU and cause havoc in the control logic. Then find your knock sensor and ensure that it's properly secured to the block.

I really doubt it's fueling since your fuel trims look good, but your pump COULD have difficulty supplying fuel at higher duty cycles. Are you certain you haven't seen a CEL for misfires?
Sounds good to me, I wanted to change spark plugs anyway and I might as well do the tests that you said when I’m in there. I do have a round pulley shaking a little bit could it be that I need to tighten it? I wish I could send videos. Would buying spark plugs directly from subaru be the best option?
 

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It doesn't have to be through Subaru, but should be precisely to their specification.

Sent from my SM-G960U using Tapatalk
 

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Are you using the ACN map or just the 91 octane. They are not equal.
 

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