uhoh this one again. V6's come with dual exhaust for looks. The C27a V6 accord only came with single. It's just for looks, it's not even dual exhaust it's only dual muffler, a single pipe comes from a single cat, passes though a singe resonator, a single premuffler, then is split to two mufflers. The only gain is for looks. Why does a G35 sedan come with single and a G35 coupe have dual(don't say HP, look on the net, I've wintessed a coupe and sedan dyno in person, and the coupe has about 2 more peak HP, would could be given for different conditions) It's for looks. The stock exhaust is pretty decent on the V6 accord, Almost every single aftermarket exhaust for it loses as much low end torque as it gains high end HP, so you lose what you gain. And technically IT'S IMPOSSIBLE to do a dual exhaust on an I4, you can do dual muffler, but not dual exhaust. If you keep the piping small enough after the Y you should be ok, you won't lose too much. So I don't really see what all the hubub is about, if the V6 can do it for looks, why can't an I4?