AIC RENAULT MEGAN VALVE PHASE I

Good morning,
due to an impasse that I had when I took my car to gas review I want to share this experience and incidentally indicate how this situation was solved.
It turns out that by carrying my result megane phase I, when I went to the gas emission test, it was denied because the co, marked 1.83 and the norm says that it must be below 1, it was past 0.83, and in the HC hydrocarbons it marked in idle 563 and in cruise 600, then they indicated that I had to synchronize the engine, the injectors, the injectors, the injectors. I changed the spark plugs, clean sensors changed the air filter and carried it again, thinking that the theme was solved, it is surprised that when they passed it again, it marked CO 0.83, that is, that mark had already improved, but in HC it continued well above although the emissions had lowered a little. He took it to a workshop and when they reviewed that when disconnecting an empty hose that leads to the AIC change valve everything, the HC began to decrease, even if it accelerated a little the minimum it reaches 1000 or 1100 rpm, after a while they went down to 900 or 800 to normal.
Someone from this forum that can get me out of ignorance and why this situation is given because when that hose is discouraged, the HCs of the vehicle are altered. ?????
I appreciate all information that can be offered to me.

Greetings from Colombia !!!!!!!

When disconnecting that hose, surely it is entering addional air to the collector (not read by the MAP or the flow) from there that climbed to 1000 or 1100rpm, this impoverishes the mixture when putting more air, then I think you can have the catalyst (if it is evil, the Lamda probe tries Bad ... I would have to look at it and listen to the opinion of others. Greetings!!