APR Stage 2 TSI boost fluctuating

Just got back from eurocars' place. We found a boost leak on the throttle body hose. Fixed it with big clamp. No more boost leaks.

Still having issue.

Fuel pump duty cycle @idle is 56%. Next step is to replace filter and check back.

Thanks for the update. I have a similar issue with my car and boost fluctuation.

I am running an f23t with eurodyne software. Mine is boosting a little higher but my guage looks just like yours under load.

I have a rev D with GFB mod. Mine is relocated to the throttle pipe so I can easily check it and found no problems I can see. I do have a mechanical DV that I may try to swap to this weekend and see if it changes anything.

May I ask, how did they find the boost leak in the hose?

Removed intake, hooked regulated pressure tester to the compressor inlet, spray with soapy water and look for bubbles

Update: (BIG WIN)
So after living with this for months I got it in to the shop to have them take a stab at it.

Symptoms were the same: consistent boost fluctuation under load 20->10->19->10 until I ran out of gear or the poor little k03 ran out of breath.
They suggested that the only possible thing could be a bad wastegate on the turbo (sad day), and quoted me the cost. I asked about maybe needing the tune reflashed (APR stg2 with 2.4 firmware) in case it had "learned" this behavior.

I asked if there was any way to reset anything it learned and they told me that the tune wasn't the issue and I had the latest revision. If I wanted to use the built in fault code erase, it would reset the "learned" values, but they wouldn't matter. So I went home with my tail between my legs after having gotten nowhere.

A week or so later I got the idea to test it again in "stock" mode. So I switched modes via turn stalk (APR). Issue still remained. Only this time it peaked at around 10-11psi and still fluctuated, though not as much. Car threw a O2 code (dp) and so I parked it.

Next day: get in car, start it up, get halfway down driveway, recognize I want it back in 93 octane mode and I should use the onboard code clear as I didn't want to get my vcds out. Switched over and cleared the code. Drove down the road as per normal (well, my learned normal that didn't exacerbate the problem), and then went to pass....


FIXED!!!!!!! totally solid boost. No new turbo, no boost leaks, just a bad PID in the programming.

I have since had the tune updated with the APR stg2 2.5 tune that addresses "Low RPM Boost Fluctuations"
Not sure if that is the same issue, but it's a broad enough term to possibly capture my issue, and may prevent it from re-learning bad behavior.

I have a feeling that the ECU learned this behavior when I first got flashed to Stg2. My clutch started going out and the ECU must have learned to compensate. After replacing the clutch, the tires were toast and couldn't hold traction that well. then winter, then more time living with it as it got worse. Just my thoughts.

https://www.youtube.com/watch?v=PXC6K1kY5Ls
TLDR: used APR fault code erase and problems are gone!