guys.. can anyone can help me correct the usage of a single pipe exhuast.. using stock downpipe i connected my mandrel bent pipe with a cheap *** exhaust.. but for some reason.. its just ******* loud but did not notice any HP increase.. or its just me.. is there any correct way of putting it or someone making one? help please..a nd do i need a defouler to do it.. check engine light seems to be ok though... thanks pepz! looking forward to your replies..