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Subaru WRX 2017 - Stage 1+ 91 Octane Map (COBB Big SF Intake Installed)

Hi, just yesterday I installed a Axle back (muffler delete). When I took my car out for a 20 minute drive (cruising not WOT), I noticed these on my monitors.

Feedback Knock: -3.87/0.00 (Sitting at 0 idle or cruising, sometimes went to -1.41 to -2.41 but for very short time and drop back to 0.
Fine Knock Learn: -1.41/0.00
DAM: 1.000/1.000

Because I saw the DAM at 1.000, I concluded that it was probably a bunch of false knocks because of the muffler delete.

The next day I took it out on a drive and the numbers stayed the same except the Feedback Knock peaked at -2.87 instead of -3.87.
I decided to try some WOT at 3rd gear and saw these numbers on the monitor.

Feedback Knock: -4.22/0.00
Feedback Learn: -3.52/0.00
DAM: 0.875-1.000
The knock and learn peak didn't change anymore from the numbers above. When I went back to cruising speeds, the knock and learn didn't go back to the -4.22. It would be 0.00 or jump to a -1.41 and then right back down to 0.00.

Today I took it out on a drive and this is what I got from the monitors

Feedback Knock: -1.41/0.00
Feedback Knock Learn: -3.16/0.00
DAM: 0.875/0.875
AF Learning 1: -3.12/17.97 (Idle would spike it from +7 and up. While cruising, it would bring it down to -1 to -2.)

It looks like the knocks are better than the previous numbers I showed you but again this was not WOT. The DAM has not changed and gone back up. However the AF Learning 1, I have never seen it that high before and I did NOT have the A/C on. The highest I have seen it go is like +9 to +10 at idle with A/C ON. But this time I turned OFF the A/C for the entire drive and it peaked at +17.97 idle. (Note: it wouldn't always be on +17.97 at idle, it ranged around +7 to +10) One thing to mention is that it was 106+ degrees out, not sure how much it would affect those numbers exactly.

It seemed like these changes only started happening after the Axle back(Muffler Delete) was installed. COBB themselves says a Axleback(Muffler Delete) does not require a tune. So it has me wonder if it's just the heat or false readings.

1. Are these numbers cause for any concern?
2. How long will it take for the DAM to go back to 1.000? (Or will it ever, unless I reset the ECU)

Also I did some data logging and sent it over to COBB to get their input on it. (Hopefully I'll hear back soon) I'd like to get your guy's input as well, especially if you've had a similar issue. Thanks!

2019 WRX
8 Posts
I don't think the muffler deletes could have possibly caused this. I think it's just that OTS tunes aren't perfect. When I was running my intake with an OTS stage 1+ tune, my DAM dropped shortly after installing the intake. I've had muffler deletes installed the whole time. I got an e-tune and the problem went away, and the car pulls harder. I'd recommend that, totally worth it.
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