new muffler, bogging down.

i just got a new high flow muffler for my 89 cavy and now when i give my car alot of gas it acts like its halfway hesitating, do i need a new ignition system? ive already got bosh platnum 4 plugs. will new wires help? im pretty sure the wires are pretty old. if i got an ignition system, what should i get, an msd? what should i look for when chosing a model #? does my car take a certian model or are they universal? thanks.

fixed it by disconecting battery cable for a while