Well this is not confidence inspiring... found this thread the other week while trying to troubleshoot a "low boost" issue with my car, and just checked back to see if you figured anything out. I plugged my AP in recently to monitor coolant temps after replacing my expansion tank, and noticed I was only seeing ~22 PSI peak (Stratified flash tune). I never bothered data logging 6 years ago when I loaded the tune, and don't recall exactly how it ran, but I assume I was seeing 24-26 PSI as one would expect for that tune. Now, boost peaks at 22.6 PSI around 3800 RPM and tapers off to 13ish at redline. WGDC is 84-86% the entire time, and ETC angle flat lines at 81-82% from around 3000 RPM onward. Threw the log file into vdyno and it came out at 174whp @ 4300 / 219lbft @ 3600. Definitely not right.
Crawled under the car today while changing my trans fluid and didn't notice any signs of oil leakage around the turbo, so maybe not the same issue you found. I guess I'll buy a DV+ and go from there.
2015 Ford Fiesta ST boost leak
Boost leak or exhaust leak?
