I have a 2003 4Runner sport/V6. I would like to put a new exhaust on it and get the most performance and not ruin anything. I was thinking about removing 3 of the 5 cats that all are after the sensors to start and work my way back from there. I have a few ideas for different configurations. I was wondering if anybody else has done anything like this and if anybody has any sugguestions.

adam

 

Adam-
Well, first of all you only have 2 real cats...one on either side of the block before the pipes T together. There is another resonator at the T that may partially act as a cat, but is more likely just a resonator. Then you have your main muffler, and finally another resonator at the end before the tip. At least that is how my V8 was. I cut everything aft of the T and added a very small magnaflow muffler and an 18" long 2.25"-3" stainless tip on the end. I have since torn off the tip while wheeling, and am going to run new pipes out both sides with the tips dumping out in front of the rear tires. If you search the forum you will find many 4th gen solutions.

Billy

 

Thanks for the input. I have a few questions though. Did you notice much in performance? How does it sound? Also I'm not positive but I'm pretty sure that I have 4 cats before the T. I believe that the V8's have 2 and the V6s have 4. All 4 of them look identical and very different from the resonator at the very end. The sensors on either side come inbetween the 2 cats on either side so removing the 2 cats after the sensors, the muffler and the resonator and replacing with 3" pipe and maybe a flowmaster should work, right?

Thanks,
Adam