Changing from a 3 Bar to a 1 Bar OS for PC01

[Scott4526]

Can someone tell me the steps to change from a 3 Bar to a 1 Bar OS, or at least point me in the right direction?


Thank you for your help,

Scott

[5FDP]

If you have the stock file, just flash that back in.

Without that file, you are out of luck for the most part.

Even without the file you can still do everything you want to do using the 3 bar operating system. Just do the changes you need for the 1 bar tune and you'll only be using the 5-105kpa area of the VE table.

[Scott4526]

I don’t have the original file so it looks like I’ m out of luck. Thank you for your help.

[kevin87turbot]

I don?t have the original file so it looks like I? m out of luck. Thank you for your help.

You can go back to a stock 1999 Silverado calibration file that has your original 9373372 OS and do a Write Entire with it. That will get you back to a 1 bar OS. At that point, you can load your VIN into it, disable VATS, and make any changes that you'd like. The primary downside to doing this is that you'll have to use two HP Tuners credits to license the stock file.
Here's a stock 99 file with the proper OS if you decide to go this route.

1999silverado1500benchstockfile.hpt

[Scott4526]

You can go back to a stock 1999 Silverado calibration file that has your original 9373372 OS and do a Write Entire with it. That will get you back to a 1 bar OS. At that point, you can load your VIN into it, disable VATS, and make any changes that you'd like. The primary downside to doing this is that you'll have to use two HP Tuners credits to license the stock file.
Here's a stock 99 file with the proper OS if you decide to go this route.

1999silverado1500benchstockfile.hpt

Thank you. I may go this route. It's kind of hard to see the 1 bar tuning curve on the 3 bar map.