Fighting with P2177 (running lean)

So today I installed the new rear O2 sensor but made no difference.
Decided to try stock spark plugs as I've read something about colder plugs creating some issues for some people with various tunes. Made no difference also.

Then I decided to try something I was tempted to do a while back but could never believe it could be the cause: try another software file.
As I have Uniconnect I can flash my ECU backwards to all stages: stock, stage 1, stage 1 hpfp, stage 2.
Currently I'm on stage 2+ which is K04.
So I flashed back to stage 2 which is for K03, stock injectors and HFC , launched VCDS and went for a quick drive, monitoring group 32 and 33.
I immediately could spot a difference at lambda control (group 33) as it was mostly at zero and with the other file it was at 18 on a freshly cleared ECU.
Big surprise in group 32, after 5 minutes idle adaptation was at -0.2 and partial adaptation (LTFT) at -2.0
I kept driving for another 10 minutes and the car kept the same values.
Went back to the garage and flashed the car back to stage 2+ (K04), started VCDS and went for a drive.
Group 33 at 18 as soon as I start the car and after 1 minute of driving I noticed the partial adaptation (LTFT) starting to climb up, reaching 19 after 5 minutes of driving...
Speechless..

Wow, doesn't "that" make you want to talk with Unitronic?
I would want to know why I am losing 20% more fuel at all times. Won't get any answers unless they care to listen...but I still would be bugging them. Let them know everything you have replaced because of suggestions and because they're the usual fix. Perhaps an email is best with links to your thread.

FINDER, what about your g/s with both files?

Today I am dropping the car back off at ABD Racing. Hopefully they can finally solve this issue since day 1 of K04. They will have a few days with the car so hopefully they can do some actual problem solving/ instead of their general "we smoked tested and nothing is leaking", or "obd-codes.com says to replace this this this and that sensor, but we dont know if it'll 'fix' anything".
So I will update yall over the weekend and if this doesnt work then I guess I have to find another shop or just take it to the dealership.

I will worry about that later. Right now I want to get my car running properly. With this weather my trims are now at 21 and it drives very bad.
I'm currently working with my contact at Unitronic to get to the bottom of this.
I provided new log files and currently waiting for a response..

Good, your tune switching results says to me there is nothing wrong with sensors, 'fuel air delivery, or leaking...and more to do with the tune.

can you elaborate?
I would love to try another brand but spending $800 on a new file is something I am not going to do anytime soon.

can you elaborate?
I would love to try another brand but spending $800 on a new file is something I am not going to do anytime soon.

I was talking about his switching from performance to stock making all the difference...not a different tuner.

Still waiting for an answer from Unitronic after I provided all the logs they requested.
I had to flash the car back to the stage 2 file as it is almost undriveable (bad hesitation when accelerating, hollow exhaust noise) with fuel trims above 20 on the K04 file.
With the K03 file the car drives much better but it obviously lacks the mid to top end power the K04 produces in a good day.
I hope I can get a revised file from them as I would hate having to start looking into a different tuner...

I finally got around to swapping my *new* maf sensor (it was a 3rd party TPI brand) for an authentic oem maf sensor. It did NOT fix my fuel trims issue and I still have the p2177 code. Also my idle now sits under 3g/s. With my old oem maf and the newer TPI brand my maf always idle'd at over 3g/s.

One thing to note though. Everytime I cleared the code and started the car (previous mafs) it always had a rough high idle for a minute or so before settling down to the 7-800 rpms. With this new maf sensor, when I clear the codes the idle sits perfectly fine on start ups.

It's been a week since I switched to the Stage 2 file and the LTFT are at -3.5%
Still no answer from Unitronic regarding their K04 file and I've also found this thread http://forums.vwvortex.com/showthread.php?5595099-K04-Running-Lean

Hey Ted, have you checked your MAF seal? Pull the intake, plug one end, nearly seal the other where you induce smoke and see if it leaks out of the MAF-to-intake connection? From there, if you have a new O2, need to check all of the connections from the intake to the throttle body...including all from intake manifold to turbo via the PCV. Smoke test it all, confirm tightness, or whatever it takes to be 100% certain all is tight. If all is confirmed tight and all sensors are good...it just might be the tune. What plugs are you using? Because curious if they run hot.

larcic said:

again its a new maf...and i never said it wouldnt run safely or not fine. just saying fuel trims wont be accurate anyway and will not drop back to zero...theyll stay around 20%

Click to expand...

Just because it's new does not mean it's not faulty. I've seen plenty of stuff come off the line and cause all sorts of issues. Even from trusted suppliers. It might be worth checking it out.

I have been driving around with the maf sensor unplugged for about 2 weeks and the car DOESNT drive any lesser. In fact maaybe it might drive a little better? maybe a placebo because the intake sounds a little louder/ exhaust sounds slightly different (might be because I also recently went 2.75" piping). Ive also noticed I dont get as much popping from the exhaust being in a high rpm and letting off the gas. Without the maf my stft stay around -10 and with the sensor it balances out to +/- 0. The only codes I throw are the p2177 & p0100 for the maf being unplugged. I have yet to notice throwing the code for the fuel pressure sensor (g247).

With the maf plugged in I get p2177 & the random g247 sensor code. I did do another smoke test last weekend and found the clamp that holds the intake to the silicone/turbo wasnt clamped down.... not sure how the shop would have missed that if they smoke tested it.

December update:
Unitronic gave me a modified file with adjusted fuel but the car didn't performed any better so I am now waiting for another revision.
While waiting I have replaced the intake manifold with a new one as I could hear a very faint hissing sound coming from underneath it, at above 5 psi when I did another pressure test this past weekend. I feared that the old one was coming apart underneath where it is joined.
Unfortunately no improvement for the fuel trims.