Lsx376 in 04 Silverado goes into reduced engine power

[Raddtadd]

Every time I build much boost my engine goes into reduced power mode. I'm doing speed density tune as well. Anyone have any ideas why?

[MikeOD]

You're probably exceeding the values in the Calculated Airmass vs tps vs rpm P1514 error table...you can try increasing that table...but what you may find is even when it's maxed out, there will be a certain airflow where it still happens anyways...some other limit in the PCM that we don't have access to edit.

If that happens, you'll need to scale the tune to make it think it's moving less air...so you'd cut the VE and IFR tables in half...look up scaling, there's more to it than just VE and IFR to make things run correctly, but it's the only way around the problem on a lot of the Gen 3 drive by wire engines.