Hi to start off its a silverado 1500 4x4 with a 4.8L
I just fixed the knock sensors and then the intake gastket leak.
It has a AirAid cold air kit and a tune from me for trans shift point and times, timing advance, afr and so on. Ill post the tune also becuase I would love some feedback on it. I have a GTP and a Ion Redline that I tuned but never a Gen3 V8 or a NA vehichle for that matter. All the cars ive tuned were supercharged or turbo'd.

The problem is that when cruiseing at 60mph it will feel like the trucks stumbling or misfireing and on the scans it shows that my timing drops like 15* for no reason, no change in tps or injector duty cycle or anything. I have no idea why it does it and any feedback would be greatly appreciated.

Thanks guys Shawn.

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