leon cupra auq 180 bhp boost issues

[lesternaylor]

Hi all.
Bit of a project I'm doing but need to iron some issues out.
Here is the spec so far.
Auq engine not forged yet.
225 injectors and map sensor
Ko3s
3 inch all the way exhaust
Special map from another running 180 auq with injectors coded in.
Boost set to 1bar
Rear 02 sensor turned off in map
Now my issue is...
It will boost to 1 bar for a split second and drop to 0.4 bar
I have done the following and it is still the same.
Shut the wastegate closed still boosts 1 bar and back to 0.4
Blocked dv still the same
Checked for boost leaks found none.
Does anybody know any other problems I could be having.

 

[ibizacupra]

checked for faultcodes.. its limp moding

 

[lesternaylor]

I have checked fault codes and none come up, I also keep erasing the fault codes incase any don't come up on the cheapo hand held scanner.
there was mechanical failure of waste gate

 

[dukemaster17]

Our cars are designed to protect themselves from egine damage.
If the boost is too high or the engine doesn't get enough fuel then it will go into Limpmode where the boost is limited to protect the engine.
The boost is limited by controlling a solenoid valve (N75) on the wastegate line by closing the throttle or by opening the DV.
The best thing to do is scan the car for codes to see what's wrong.
Look at the fuel trims for running lean block 031 on diagnostic and also look for MAF readings block 002 and last look for O2 sensor problems.
To see for boost problem log block 115 on diagnostic and there you can see Specified Boost VS Actual Boost.
If you exceed the Specified boost pressure then you are going into limpmode.
The specified maximum boost for petrol engines is 14PSI.

 

[J_hunt17]

Replace the n75 valve,
Had exactly the same on mine, just tried a other n75 and its back to full strength again.