DS3 THP 155 power loss

[Kurbla]

Hi, a couple days ago my DS3 got constant power loss, like it is 70hp. I take it to Citroen service and they change oils, filters and they cleaned valves. After this car was good for 2 day and power loss come back again.
Does any1 know what is problem?

[Chris_Blue]

HPFP?

[V3nn3tj3]

If no faults occour, check ltft. If this is above 20 my best guess would be timing. Either the chain or the inlet cam started to slip.
Only reason i know for powerloss but no dash lights.

[Kurbla]

Tnx, it can be HPFP. Car have 120k and it is never changed.

[Toxic]

I have heard that there is also a Turbo Solenoid valve at back of engine that can case similar issues too.

[Toxic]

Also check to boost pipes for any leaks.

[Kurbla]

Thanks Toxic, I will check it.

[Kurbla]

Update: It was oxygen sensors! /facepalm

[Barola]

I have heard that there is also a Turbo Solenoid valve at back of engine that can case similar issues too.

I had a code P0243 and no boost until 3000 RPM than turbo starts to kick in quite powerfully . Tried putting a new turbo valve solenoid (on turbo) the fault code is still present. Returned the old turbo valve solenoid. Checked the turbo vacuum valve solenoid as on your picture firstly it it not hold any vacuum you could blow thru tube of this vacuum valve. After couple of tries the valve started making vacuum obviously rubber membrane inside started working again. I put it back no more fault code P0243 but car has a very low turbo boost maybe 40% of a full turbo boost. What could it be any opinions? Maybe the turbo vacuum valve should be changed to new but again there is no fault code? Thanks for any guidance.