I am currently looking at a 2014 A7 TDI with 47k miles on it. I searched the VIN on the Audi site and it came back as having the modification completed and remaining emissions warranty. As a long time diesel truck owner I am a big fan of diesels and this car will be used on the highway quite a bit so I feel it’s a good fit for me. Here are my questions:

-Did the emissions modification hurt the fuel economy and/or reliability of this engine?
-Are aftermarket modifications available to delete emissions restrictions, increase torque/hp, and/or increase fuel economy?
-What kind of real world fuel economy numbers are guys seeing on the highway with or without aftermarket modifications?
-How is the reliability of this engine?
-Any particular things to look for?

Thanks in advance!

 

I purchased a 2014 A8L 3.0TDI that had not been "fixed" earlier this month. I was very impressed with stock performance. Of course I had to take the car in for the "fix" to make it smog compliant in California. After the fix I did notice a drop in power and I noticed that the mile estimator dropped considerably. All of this was in line with what the dealer told me to expect.

Dealer said expect 10-20% drop in mileage depending on how you drive (normal - maniac) along with minor drop in power ( but enough that you could notice it )....... although I have only been this way for a week, it seemed that the dealers description was accurate. The car still has plenty of power.

Well there are upgraded tunes available for these motors. Yes there are tunes that support (Removal of DPF, Adblue, EGR, and/or Intake Swirl Flap). Having said that I don't know what those are.... yet.

I did purchase and install (using their Flashzilla installer) a Malone Tune (stage 2) which supports the removal of those items and the tune provides for a huge power increase. With the removal of those things it takes the car from an after fix that is something less than the stock 240/406 to 305/490 with the deletes.

I have installed the tune without doing any of the deletes and the increase in performance is dramatic. From the little bit of TDI browsing I have done it seems that others have gained their mileage back by also doing something related to more free flowing cat/exhaust.... need to do more reading.

Just remember power only comes from fuel, you have to burn it to make it. Anyway, the power increase put this car waaaay beyond pre fix power. This is not a subtle change, you will notice it everytime you drive it.

Anyway I have more studying to do as this is my first diesel. I live in California where emissions test are stringent so I have to see how/if the deletes etc can live within the law. If not, I am fine because the power from this Malone Tune is fantastic, smooth and feels like OEM until you put your foot down.

Note: I will track my mileage and report back, I don't think it will be all that bad. Having said that I purchased the car pre - fix and prev owner never filed a claim. So I just got 9664.27 from VWOA! so I have been well compensated for any lost miles per gallon due to the fix. Yes I bought a used car and got almost 10K back after buying it.... When I bought it, I was completely unaware of any this, I only bought it because it gets better gas mileage than my 07 4.2 A8.

 

I took my 2016 A7 TDI in for the emissions 'fix' three months ago at 25,000 trouble free miles … now it has thrown the "check engine" light twice in 500 miles for the particulate sensor warning. I hope this isn't a pattern that is a 'feature' of the new emissions changes. Anyone else seeing this after the 'fix'.

 

 

I purchased a new 2016 A8L tdi last April. I nine months I've had the CEL come on more times than I'd care to mention. Three times it has been the oxygen sensor and twice the nox sensor. Audi is claiming that it's caused by short distance driving. Anyone else having similar issues eith thier new tdi?

 

 

Thanks for the reply. I think Audi is back pedaling due to the "fix". I may have to pursue legal action.

 

Ours has the fix but don't usually drive short distances, my typical drive is 45 min. We have not had any issue in the 10k miles we've owned. Search for "dpf regeneration" if you're not familiar with one of the impacts of short trips on performance of modern crd emissions systems. It's conceivable the fix has changed the parameters that might make it more susceptible to dpf and system behavior; it's also conceivable that something else is wrong. For grins you could try intentional periodic longer runs that would permit regeneration and see if it helps -- at least you could tell your dealer if it doesn't. Good luck in reaching a resolution.