Little power a volskwagen pole 1.9 sdi

He was made a change of hoops at the reason that the lid joint had blown and after this work is a decrease in the power of the engine even does not pour black smoke due to the sppa, as he strives it to the engine, since he already scan and does not give me any fault in the system if someone has an idea I thank you.

Hello, look at it the flow if it carries, because if you fuck you, the flow takes away power, look and comment, greetings

Hello to know better you have to install the Scaner and look at the continuous mode how the MAF sensor works since that sensor measures the amount of air aspirated by the engine and on it gives it the right amount of fuel greetings