orion

I hava a Yamaha YQ50 Aerox R 2009 and i have changed the exhaust to a technigas but the old std exhaust has 2 metal pipes at the front end, one thats welded up and one that goes to a black box which could be a sensor of some sort, which then goes else where? The new exhaust does not have these pipes on, so i have tucked the rubber pipe away, with a bolt in the end to stop any dirt getting in etc. Anyway the bike now performs worse than before, so i took out the bolt possibly a slight improvment but still runs bad, Wont go up hills very well, not that it did before. I have not done anything else to the bike like removing the front washer or changing the rollers, filter or jet size changes etc yet as i wanted to do one job at once to see how each improvement went on. Does anyone know what that sensor thing is? or any help