Car has been through multiple combos and currently runs a P01 2 BAR, FLEX FUEL enabled tune.
I've flirted with disaster dozens of times, running 19-20 (or more)# of boost, and no ability to tune fuel about 2 bar.
When I did the Flex Fuel enabled OS, and wired up a flex fuel sensor, it was because I had worries about being out somewhere, low on fuel, with no E-85 around...
That "cruising" idea has never happened, so I'm wanting to just choose an Ethanol/E-85 ONLY (or e60, e70 or whatever), non flex stoichiometric setting, and go back to a 3 bar RTT OS.
At least then, I'd be able to "tune" fuel above 15# of boost...
I also test ethanol content already, so can easily reflash if content is off what it always has been.
ANYWAY...
I have the current 2 BAR OS (still in car),
a STOCK 1 bar OS, and...
a 3 BAR OS (that WAS in the car a few years ago)
Note: ALL THREE have been used on this same car in the last few years
The QUESTIONS...
1. Can I simply WRITE ENTIRE the old (previous) 3 BAR OS that I ran a few years ago?
or...
2. Would I need to WRITE ENTIRE the "stock" 1 bar OS, I saved, and then UPGRADE to the 3 BAR?
As said, all THREE operating systems have run this car, this engine, this ECU, at some point in the last couple of years...
Thanks in advance...