Fault code p0234 vauxhall signum 1.9 150

[Clippy6]

Please help after giving the car a good going it retreat's and falls into limp mode. It can be cleared by Thurning the key. Was wandering what it could be, I seem to be suffering from poor mpg too could this all be caused by the overboast problem. Any ideas?

[northpole]

it's called limp mode... the ECU notices an over-boost and decides to rain it all in... as soon as you turn the car off it goes back to normal... over-boost means that either the intake is dirty/ one off the boostpipes is leaking or comes off/ a leak in the vacuum lines/VNT mechanism on the turbo is stuck/leak in the intercooler /or the turbo actuator or boost valve has given up... it could also be a dirty MAF or boost sensor so all in all you need to check the system.... for all those bits.

nothing too difficult but very labor intense i would start with checking the big boostpipes/ all the vacuum pipes/ than check the MAF and Boost sensor (they can be cleaned with an electrical cleaner) than i would take of the front bumper and check the intercooler... but in most cases it is one of the pipes..... if that all seems fine... than you can clean the VNT on the turbo with a foaming oven cleaner such as MR Muscle(meaning you need to take of the hotside of the turbo, remove the downpipe, and spray it right into the back of the housing where the VNT is than work the lever until it feels smooth when it is close it all back up and go for a run of at least 40 miles in 3th gear so the turbo gets red hot and burns the ovencleaner and all the soot off)

the turbo actuator can be tested with a vacuum pump but if you don't have that it's best to have that checked by a garage/ and the Boost valve is the one that connects to the turbo actuator... it can be cleaned with electrical cleaner spray it in the bottom and top pipe and watch all the dirt coming out while you do so... you can blow on both pipes to make sure it works but usually the electrical cleaners pressure is enough to notice if it isn't functioning properly.

But knowing the vectra's the chance it is just a boost leak is greater than the VNT mechanism being stuck.

[Clippy6]

Thank you for the reply a great bit of information will get onto it tomorrow