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Discussion Starter · #1 ·
Tried to search with no luck. Hopefully not because doing it from my phone. To make story short, 17 SS manual trying to tune it with hp tuners. Just have rotofab. On the laptop shows knock retard all the time, at part throttle pulls 3-4 degrees and at full throttle seen 6. Stock tune still. This is all the time. New fuel also. Anyone? Just read one post but little info as false knock retard
Thanks
Jay
 

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2014 SS, SOLD!
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You're using 91-93 octane fuel?
 

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Discussion Starter · #3 ·
Yes. 92 all the time. Will try today with a vp octane booster to see if that’s the problem but really doubt it.
 

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I had a bad knock sensor cause it. They are cheap. Buy from dealer directly
No. The engine knocks from the factory.

All gm engines knock from factory. If you want to replace the sensors go for it but you will see knock after that too. Knock sensitivity duration and decay is very high from get go. You will see knock on normal shifting from tipin.
 

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No. The engine knocks from the factory.

All gm engines knock from factory. If you want to replace the sensors go for it but you will see knock after that too. Knock sensitivity duration and decay is very high from get go. You will see knock on normal shifting from tipin.
While that is true that you will see some KR on the stock tune, mine in fact was not the standard small amount of KR and was caused by a bad knock sensor.

Verified by a very good GM Tech with thier pricey tool and the abnormal KR was gone after replacing the sensor
 

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Pull 5 degrees of timing or so from the high and low tables and see if it goes away. If less timing doesn't make a difference then look at either replacing the sensors and/or check the wiring.
 

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Discussion Starter · #9 ·
Crap already did. Why is that ? I Did just to see if it has something to do with the gas. Will test today
 

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Discussion Starter · #10 ·
Welll no knock retard today. So we don’t know if it was the octane booster or the rattle fix on the exhaust. Will burn all the gas and fill it up with no octane booster. Let’s see if it stays away or comes back.
 

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Discussion Starter · #11 ·
Well the knock retard is back. We tried raising the timing to 20 but is pulling 4 back. We’re going to try different knock sensors just to give it a try. If nothing changes we’re gonna try a different gas station. This thing is driving me crazy.
 

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I am confused. You were getting knock so you increased your timing? That would make it worse. You need to reduce your timing to lower your risk of detonation. Just pull say 4-6 degrees from high and low octane tables and see if it goes away.
 

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Discussion Starter · #13 ·
No. We added an octane booster and fixed a rattle on the exhaust and it went away but since we did both at the same time we do not know what fixed it. Now it came back. We are trying to tune it but even at stock timing it’s pulling 2. Today we will try different knock sensors. Let’s see.
 

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Inception Date: 1 March 2017, Chevy SS Sedan, White, A6, Spare, No Sun
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Do not use an octane booster!
Yep, I learned that the hard way. I've been using Chevron 91 for decades but then acquired OCD and started using Techron additive. I developed a knock and failed to connect the cause-and-effect. So, I stopped using the stuff, and the knocking disappeared. Sometimes I'm my own worst enemy~🥸
 
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