Mitsubishi outlander 2.0 di-d 2008
Hi OK so I'm at a loss here.
last year I had my egr changed as I was getting the po488 code come up and eml on, car was a little lumpy as well. Garage changed this at same time as doing a cam belt change.
Garage said it also could do with a new throttle body to completely cure the problem.
So I got a new throttle body and fitted.
The lumpy idling went which was great and no eml on, so I thought problem solved.
took car for a drive and it felt a little under powered, wasn't until I got up to higher speed that it went into a kind of limp mode (but no eml). I found that restarting the engine temporarily cured it, but as soon as I get upto a certain speed it goes straight back into limp.
when plugger it still brings up codes po488 also brings up another code for turbo underboost.
before I shell out a fortune at a garage is there anything anyone would recommend trying first.
Amy help would be much appreciated.

 

Check the vacuum line steering the turbo charger's valve as well as solenoid conrolling the vacuum.
Check the air intake hoses to/from turbo for cracks or gaps at connection points.

 

Update
changed the boost pressure sensor and it seems to have done the trick. Drives spot on now. So fingers crossed.