Knock like crazy? LS 3 Corvette

[Pierrel]

Hi,

2009 C6 Z51 LS3 corvette
Had a guy come in to change a power steering hose. Found the air intake was cracked badly at the coupler (after the MAF sensor) just by the TB.
Replaced the air intake and went to take it for a spin just to check trims were alright. Trims was fine, but it was showing KR and pulling timing very often and alot.
Could not hear it knocking anytime though. Mostly at part throttle (Closed loop), around 3000-4000 rpm with 0.6-0.8 g/cyl it pulled up to 10 degrees.
But it also pulled up to 2 degrees at lower loads between 1200-3000 rpms.

Ive attached a log and tune that was pulled out of the car.

Car is from my understanding stock, except for Pfadt tri-y headers.
Theres nothing rubbing or touching on the exhaust or on the engine. No audible knock, could it just be the sound of the headers making this?
Pulled the exhaust to check on cats but they were all intact and fine
Thanks!

[biholliday]

your tune file will not open. you are commanding 18 degrees in that area so it looks like false knock. are your motor mounts good? mine looked good but were not and my headers were hitting the frame rail under heavy load

[Pierrel]

Thats wierd, I read it from the car using version 4.8.7. Could that be the issue of not being able to open the file? I uploaded it again, please try again
Should be around 26-28 deg commanded in that region in the stock high timing table.

[blindsquirrel]

The tune file is all stock (or close enough, I did not check the OS ID on the file I used for compare so the minor diff's could just be that), this is not a tune issue.

If you increase octane AND decrease spark timing and it still does the same thing in the same conditions, it is not something happening inside the cylinder. It's some other engine noise, or chassis/exhaust/suspension.

[Alvin]

It could be just knock sensors. When they go bad, they get super sensitive or very quiet. Torque is important when installing new.

[JayRolla]

It sure does look like false knock like they stated. You can tell when your WOT it's not showing much of any knock, just in that mid throttle area. If you have checked over everything, I would look into the knock sensors. I would even try to loosen them and then re-torque, they don't need much tq at all, just enough to be snug. If you do replace them, make sure to go OEM sensors and nothing from the part store or aftermarket.

[Pierrel]

I'm getting the car back on Sunday to continue work.
Have new knock sensors on order, and will begin with lessening spark and see where that leads. Already running equivalent of 93 octane

I'm quite sure it's false, there's absolutely no rattle or anything from the engine. Will check motor mounts just in case.

The tri-y headers won't give some sort of weird pinging sound that could trigger the knock sensors?

Thanks guys!