Back to stock

[95nBlown]

Is the "virtual" read that comes from the HP Tuners servers for the SIMOS 8.4 ECU the one that needs to be flashed to the ECU if going back to stock?

New to the Audi tuning game, as I didn't have my original 2010 S4 tuned several years ago. I now have a 2011 S4 and am working with a talented tuner. However, I want to make sure I have a path back to stock for any unforeseen challenges.

Thanks all..

[ELaw]

This probably doesn't help much but in my experience there are two options for this, and I'm not sure what the difference is... maybe someone from HP can explain?

When I first got the HP setup, I "read" the ECU on my '14 A6 (which has about the same engine as your S4), which as you say probably just pulled a stock calibration from HP's server. I then proceeded to tune the car.

Later on I took the car in for inspection and it failed for emissions readiness and I thought the tune might be a factor so wanted to flash it back to stock. I loaded the stock file in VCM editor, went to "flash" and was presented with two options: one was to write the current file, the other was to "revert to stock" or something like that. I'm not sure if the two would have done the same thing (assuming an untuned file is loaded) or not.

[95nBlown]

Hmm.. That's interesting.. Well, I'm about to write the initial tune from my tuner. I trust him.

Here goes the neighborhood.. lol

Thanks for your experience here.

[Exley]

I'm on Simos18 but my experience may be similar. The tune that HP Tuners gives you on the initial read is a stock calibration. In order to make the calibration modifiable the first write you do modifies some other areas in the ECM. I haven't tried to go back to stock yet, but I believe it would look something like this. If you write the stock calibration the car will drive like stock, but that initial modification will still be present to allow OBD calibration changes. The VCM Editor also has a "Return to stock" function that I believe will remove the initial modification.