Engine advice sought

[Harrythedog]

As I've stated in recent post I've had an inlet manifold fitted to my W211 320cdi and have noticed a slight drop in acceleration compared to whoomph I had and also the mpg has gone down, can't seem to get over 34 mpg on different types of runs. Is this par for the course or does it need tweaking in any form.
All suggestions gratefully received


Thanks

 

[jaymanek]

Id say a hose is off somewhere.. you have an air leak...

 

[Harrythedog]

The acceleration is there but not the lift off I used to get at any speed between 0 to 90

 

[jaymanek]

Rev the car at stand still and see if you can hear anything...

 

[Harrythedog]

It sounds fine Jaymanek , revs right unto 4500rpm max (rev limit I assume)