A4 1.8T boost pressure issue

[Tony Hoffman]

Hi all,

I am having an issue with an A4 1.8T that I'm unfarmiliar with. It is
overboosting, an causing a code of 17963 - P1555: Charge
pressure:Maximum limit Exceeded. I see a max of about 13-14PSI before
it throws the code and goes into a "limp" mode of sorts. After that,
It won't allow anything more than about 1-2 PSI. If I clear the codes,
I get a 13-14 PSI run every time, then shutdown. It shuts down
immediately after hitting boost, even with the throttle still floored.

Background of the car: It came into the shop with a blown engine(hole
in the oil pan) and we swapped it. I ended puting an APH engine into
it, but put the variable cam tensioner into it as well. It also has a
new turbo on it. I don't know about the turbo wastgate adjustment, but
it was positioned the same as the old one, by my measurement. The
thing that has me leading away from that is the fact that it can
reduce pressure with no problem after going into the limp mode. BTW,
all boost measurements are via a manual boost guage I have T'd into
the intake.

Thanks in advance,
Tony