Rev issues

[Tshepo]

Good day everyone
My name is Tshepo from Johannesburg South Africa and I am new in the group.

I have a Citroen C4 running Ep6 engine (Turbo)
My issue is the car starts and idles but it does not rev.
When the car is turned on and the accelerator is depressed, the throttle body butterfly opens up fully, but when I run the engine and depress the accelerator I'll have no more than 1500rpm and it is not consistent. Any idea as to what may be the problem.
Your help would be much appreciated. TIA

[GiveMeABreak]

You'll need to get it read with a diagnostic code reader - it may be limiting the engine speed if there's a fault. Once you have the fault codes, put them up here with the VIN.