Car is overboosting somethimes

[dixie]

First of all my car is flashed almost a year ago,first 8 months boost was always around 18-19 psi,but after 8 months I noticed car was holding down power and I noticed boost was going till 24 psi and dropped again till 18 psi after 1-2 seconds,I checked wastegate bolt and it was fine.
Next day problem was gone and boost was normal,but after a month it happened again for 1 day,next day back normal,yesterday same problem,it seems like wastegate is not working but I don't get check engine lights or dtc codes.
Someone got an idea what could cause this?

[cooler2442]

Is yours an 07? If it is check the spark plugs TSB. The same thing happened with mine when I had the old spark plugs I would boost to 23-24 and sometimes it would go into limp mode. But if you have an 08+ I don't think you need new plugs so it would be something else.

[dixie]

I have a 2008 , I had today an oil change at the dealer and they ordered new plugs anyway because they didn't know I had the good ones.Hope this solves the problem.

[dixie]

Got oem software back in,problem solved,next week time for BSR flash