DAM dropping is about the time I really start to dig into a tune if I wasn't seeing a lot of FBKC or FLKC. Maybe you just got a bad tank of fuel if this just started, however, there are a few things you can do. You can clear the ECU so that it doesn't have the values, you can also reduce global timing to see if the knock/noise goes away, or you can flash a different map that may have less timing. All can be done on the AP and I would progress in the order above.

 

You can clear the ECU so that it doesn't have the values

I started with resetting the ECU. DAM came back to 1.000. I drove back home and it stays there. FBKC and FLKC look ok now, shows "normal" number. I'll watch this closely. Thank you sir!

I would probably get a compression and leakdown test before experimenting any further.

Thank you, I'll keep those tests in mind.

Flash it with the Stage 1 OTS 91 ACN map instead, to see if it does it again.

Thanks! I'll try that if it does it again.

I'd start with putting an OEM filter back into her.

Do you think the K&N is a bad idea ? Thanks for your reply.


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Again, thank you all.

--
SomeOneQC
2016 STi
Photos here

 

Hi there,

Well, when I came back from work yesterday, a 65km ride, the DAM drop bellow 1...

Should I worry ?

Usually I only saw Fine Knock Learn going down to -2.80, same for Feedback Knock.

Image Link


Since the DAM drop at 0.938 (or even 0.875), the Fine Knock Learn fluctuate a lot.

This morning, DAM was still at 0.938, even after a 40 minutes drive. The Fine Knock Learn got to -7.74... :|

Image Link


Could this only be bad gas ? Something worse ? Should I do a ECU reset by reflashing the same map ?

The only thing I change on the car, a few month ago, was the air filter. I installed an K&N.

I run Cobb map Stage 1 - 91.

It's a 2016 STi with 41986 km on it.

Thanks in advance for your feedback.

--
SomeOneQC

With the computer already correcting repeating knock events to where you have -7 fine knock and you still have consistent feed back. I would be concerned. I would probably get a compression and leakdown test before experimenting any further. Consistent feedback knock issues and heavy fine knock numbers AND a dam drop even after the fine knock learn is very problematic. Be prepared. Bad gas or not it seems the damage may be irreversible.

 

Flash it with the Stage 1 OTS 91 ACN map instead, to see if it does it again. The map is for us who live in california, arizona and nevada with crappy gas.

 

I'd start with putting an OEM filter back into her. -7 knock is a lot. I also find it interesting that it's advancing the timing .5 on the learn. I have never seen that before....

 

never understood why people dont stick with oem intake / filter if they're not gonna custom tune...

 

Thanks everyone for all the infos. I learn my lesson. No mod except if it come with a pro tune, even for an air filter

I revert back to the OEM air filter and since everything look normal. DAM stays at 1. Fine Knock didn't catch anything. I only got -1.20 on the feedback. Compare with the K&N installed which was giving me negative numbers in both knock sensors. Even saw a -4.x on the feedback.

I'll keep monitoring this. Thanks again.

--
SomeOneQC
2016 STi
Photos here

 

My DAM stays at 1.0 when on the 93 tune, but when I leave my area and have to switch to a 91 tune the DAM drops to .8 something.

Assuming you're going in for a tune and have the factory airbox, do y'all recommend the OEM filter, the K&N, or the AEM dry filter?

 

I think the vast majority of people on here will suggest the OEM filter on the OEM air box.

 

The Cobb SF intake and air box works at least as well as the stock air box, but only with the proper (OTS) tune.
It's a bit noisy, with all the whistling and wheezing (sounds like an old man dying of COPD), but it works well enough. Highway cruise efficiency is slightly improved with that intake, but there's no discernible difference in power/efficiency once you go into positive boost levels.

I too use the AP to monitor knock, in order to assess the quality of local gas.
The only fuel I've found in my burg that is compatible with my car is Husky 94. It has ethanol, so fuel economy is slightly reduced, but it burns clean. IMO, a clean burn is paramount to a healthy engine.

 

I’ve had the same problem dam dropped to .500 and feedback knock was -11 but i dont hear anything from the engine bay area or any rattle and even after i reflashed it still the same numbers .

 

I’m in stage 2 tune. Intake and downpipe. Don’t know what’s wrong .

 

Do a compression test.

 

Hey there, i did my compression turned out to be good Before I installed everything I’m running stage 2 cobb ots tune.

 

The compression test was good before you broke a ring land. Now you do another compression test to confirm.