It is POINTLESS flashing the car back to stock for a visit to the dealer.

Once the "non OEM calibration" code is set, it is there forever, it cannot be deleted, and actually it get's reset new every time the ECU is flashed, even with a stock tune, even using the dealers diagnostic tool. (the time/date and mileage for when the code was triggered updates with each flash).

You cannot hide it, it will always be there.

So actually if you flash the stock tune back in the day before you take the car to the dealer, they will see the date/time of the code as yesterday, which makes it even more obvious that you're trying to hide it.

 

It is actually 100% critical to flash back to stock before a dealer visit, and something that we stipulate in our instructions. The tuning process changes the checksum. If the tune is left on the car, and a dealer does a partial software update rather than a 'flash as new', then it will update the checksum incorrectly and the ECU will be bricked - rendered unusable.

Even if it is done as a 'flash as new' update, if the car is not put back to stock prior to the update, then the programmer is not able to be erased, read with the new software version and the tune updated. Now the programmer is bricked.

So we STRONGLY recommend all our customers return to original programming before dealer visits.

Beyond that, what you're saying isn't untrue about detect-ability, but nonetheless I would still rather not have the file on the car at the time. For several reasons we have mentioned, including the fact that non dealer diagnostic software can throw the same code so there is some plausible deniability.

 

Don't flash me bro - they make these covers:


It's not uncommon, especially with newer model years for dealers to install updates via the OBD port.

 

I would also like a piggyback tune. Thanks for the link. My friend uses on on his GTI and it works great. He just unplugs it and there is no trace you did anything. I think that would be the best way to go until the car is out of warranty.

 

xe25steve have you tried the rennchip tune yet? If so how do you like it?

 

The VAP tune is much stronger than a piggyback. I had a piggyback on my 2014 Audi S4 which made an increase from 335hp to about 375. It was good but not always smooth. It took minutes to put it on or take it off. I have the VAP on my R Sport which has move it from 340 to 420 hp or so. The impact is major on the Jag. Way smoother than a piggyback and I believe much more power. My car was quick before now it is very very strong. Considering the number of guys that have put the VAP tune on the 340 hp without an issue why bother with the piggyback.

 

I have the VAP tune on mine as well and to be honest I am not sure I can tell any difference in power. Maybe I didn't push it enough before or maybe its just me with bad judgement which is very possible. I am going to wait till a dealer visit to switch to original file and see if I can tell the difference then.

 

Interesting, my car is a different animal with the tune. Maybe your new program did not take hold or something. Night and day difference for me. I mostly drive in dynamic mode, when I add sport to dynamic it is very strong. I only add Sport when on the freeway.

 

I was testing all in Sport mode, but I am not certain I paid close enough attention before the tune and if I really pushed the car much. I thought it was fast before and it is fast now that's the best I can explain it. I hope once I go back it will be more obvious to me.

 

75-80BHP, you should notice a big difference. If you plug your programmer into the OBDII port now and select the tune file to flash to the car, what does it say?

 

What do you mean by way smoother? What will cause the difference? Just curious. While I intend to get a proper reflash later on down the track once I am sure any build bugs or quality issues are out of the way with the engine, I for one wanted to limit mods to removeable/undetectable piggyback unit while the car/warranty is still very new.

 

What about two computers? One with the flash, and one never touched? Back in the day, computers cost around 80$, and were easy to change. Right behind the glove box...

 

I think you will find they are considerably more expensive than that, these days, and more difficult to swap over (electronically, not physically.)

 

More linear acceleration with the VAP tune. The piggy back on the S4 was more zoomy and less predictable. Would also occasional cause a cel.

 

Did you end up going to Hornburg? I'm in the same boat as you, have an ECU upgrade from VAP, but need to take the car in for scheduled maintenance, and Hornburg is the closest to me. Wondering if I need to detune or can just tell them it has it, and if they'll care or not.

 

I believe you have to detune regardless, they would not be able to run any updates if the system was not stock, unless they would not be doing any updates. But I would not risk it anyways as it could cause many more serious problems. If you took the time to read the earlier posts the tune guys actually say it is absolutely critical to flash the system back to stock before dealer visit.

 

If you read our supplied instructions, they say always to return to stock before a dealer visit. For a variety of reasons, however if the dealer updates your software and you don't flash back to stock first, you risk at worst bricking the PCM, and at best, ending up with a stock file on your car and unable to flash the MOD file onto the car without us selling you a new programmer.

 

I recently made a post summarizing some of the downsides of tuning. You can find it here: https://www.jaguarforums.com/forum/f...tuning-206030/