[hoffo]

A few weeks back I noticed my 2015 Fiesta ST seemed slower than normal, it doesn't put me into the seat like it used to when accelerating hard. I suspect this may be a boost leak or similar issue so I took the car into my local dealer Kings Ford. They said they couldn't find anything wrong but the guy that talked to me said they found no codes, so sounds like all they did was check the odbII codes. I know these cars don't throw codes for boost leaks so I'm guessing they didn't do any actual pressure tests or diagnostics. I have a bluetooth odbII scan tool and the torque app on my phone so how much boost should I be seeing on a stock FiST in 3rd and 4th gear? Also how soon in the rev range does the turbo make full boost?

 

[djwhiplash2001]

Full boost should be there at about 2400-2500 RPM. I think the ECU targets 18PSI? Make sure the Torque boost value is reading at the manifold rather than at the turbo.

Odds are, loose boost clamps.

 

[me32]

Check all the hoses to the intercooler/turbo/tb. There were issues at least on the 2014 st where the hoses would get loses an leak without knowing and would cause boost leak