[Ashs2017gt]

Hello everyone. I bought a 2017 Gt last year so I thought start with the basics I put a cold air intake and a custom tune at the local dyno shop. He must of ran it 25+ times on the dyno( over 3 visits) it keeps pulling 8 degrees of timing and can't figure out why. Has anyone heard of this?

 

[q6543]

Could literally be anything, false knock? Did he put known high octane to check?
Maybe there is an issue?
Does it have headers or aftermarket x pipe? They can false knock too.

your tuner should be able to diagnose what’s goin on easily

 

[Ashs2017gt]

Yes it does have x pipe roush mufflers . I run 91 octane. Hard to find anything higher. And that's why I'm on here my tuner can't figure it out. And he has 15 plus years just tuning. And mostly mustangs.

 

[SNK VNM]

What happens when octane booster is added?

 

[Ashs2017gt]

Nothing. Tried that aswell.

 

[SNK VNM]

So 8 degrees is pulled with and without octane booster? Sounds like false knock if that's the case. I'd start checking the exhaust first. Any codes?