Exhaust Dos and Don'ts.
I put in the 70 Series Flowmaster muffler along with the custom Y pipe that the guys at St George Muffler and Radiator did for me (love these guys!) I had a 70 series on an LX470 and it was phenomenal! A sweet, mellow, beautiful V8 rumble, never raspy, no drone, BUT... a V6 is a different animal. On the 4Runner it was none of those things. It was too loud, there was a bad drone and it just sounded like crap. So after twenty miles on the highway I was back in the shop and we reinstalled the original muffler with the new Y pipe. The redundant cats disappeared. In my opinion this is perfect. It is a bit more throaty because the second cats are gone, but it's pleasant! This, along with the TRD intake, AFE dry flow air filter and the pedal commander, it runs WAY better than stock, even with the 285 tires. This is the way Toyota should have built it.