exhuast 02
 

im about to do my exhuast but i dont want any cats. and i have a 3rd o2 sensor, could i just put a spacer on it to get it out of the flow of exhuast so it works? they sell them on the subaru.com, im still debating whether to go with real dual,or un-equal length headers connecting to single then to dual... anyone got some ideas? ive got two 2.5 inch piping that im going to use for dual if i decide to use that, and use a flowmaster 40 or 44...