how can i fix my 2003 Zafira?

There's a valve (a boost valve apparently) behind the battery which has two pipes going into it and wen i remove one of the pipes the car will go, but it seems to be the car has no power wen the pipes off.. And for me to put the pipe on the car wont start. No one seems to no wot the proplem is, can anyone recommend anything or give me some advice??