The 4th gen 4runner v8 has 3 cat converters, plus a resonator in the rear by the tail pipe, can the center converter just before the muffler be removed? The O2 sensors are at the converters comming from the manifold, not the converter near the muffler.

Any thoughts?

 

I bet if you did you would gain about 15-20 HP!!!!!!


A friend of mine did that on his v6 m3 and got 15 at the wheels!

 

You're from PA I see. Are you near a metropolitan area that requires an emissions test? If so, it may not pass.

I thought there was some sort of fine for tampering with emissions equipment on road-going rigs, not sure though.

Jason, I'm pretty sure M3's never came with V6's, only I6's.

 

You know what I meant.

 

 

Removing a working catalytic convertor is a federal offense with up to a $100K fine.

 

So don't remove it. Just gut it out, stick a pipe through it, and weld it back on.

I didn't like the way the truck ran when I removed mine... no low end... and the tach went screwy every now and then . So I bought a high flow and got my low end back without sacrificing any top end, and the tach went back to normal. I'm happy.

 

One of the stupidest posts I have read. Ever. Anywhere. Remove it, I hope you get caught.

People removing emission controls on their vehicles don't deserve to have a license or any vehicle. They are same pieces of crap that litter the trails, make new trails where prohibited, shoot up signs, dump oil down the drains, etc.

There is no way you get 15-20 hp without the cat.

What a joke, remove the cat...stupid, stupid, stupid...

 

my friend was stranded one morning right before finals at school. he called me and i picked him up and went to school. luckly i was off work tha day and he didnt have to work till 4:30. after school we went to his 84 trans am and tried starting it, it would go for like 100 feet then stall. we figured out it was a cloged cat.

went home, got my drill and ended up drilling about 10-15 3/4" sized holes in the cat. thing started right up

it sounded god aweful, but it had more power than ever he then gutted it out soon there after

he totaled it before he needed to smog it though

 

I SERIOUSLY doubt that the cat on your 2003 Toyota is restrictive enough to net you 15 hp. And Jason B, I always respect what you say, and your opinion, but I'll have to see the dyno sheets on that BMW... M3's don't gain 15rwhp w/ no cats... more like 3-5rwhp. I doubt a lower-end motor would gain more, unless it's got forced induction. There are better ways to gain more hp... look at your stock exhaust for answers or ideas. Besides... freer flowing exhaust will gain you high-end hp, but you'll lose low-end torque... why would you want to do that to an SUV designed primarily for towing? W/ the money you'd spend on fines for removing the cat you could easily pony up for a TRD S/C. It's smog legal and will add WAY more than 15hp...

I'm no enviroment nut by any means, but I'm w/ the guys that are against removing your cat!

J

 

The 2003,and 04 4runner w/calif emissions have 3 converters on the v8 motor, and only 2 on the federal versions (which are still legal in all 50 states) The reason Toyota installs the calif emissions is to introduce it into the market for the mandatory emissions on SUV's in 2007.

While both version depict the same HP, the brake HP (power at the rear wheels is closer to the advertised HP). Also, the Federal versions get better gas milage.

 

It's true and actually a little more than 15. You can also check out roadfly BMW board and ask the owners there for their personal experience. The cat is removed and replaced by a high flow mid/track-pipe, cat gone, replaced with this.

http://www.activeautowerke.com/exhau...ckPipe-E36.asp

+26 WHP for 95 M3s
+13 WHP for 96-99 M3s

Then add a new muffler and get about 5-8 more hp more at the wheels.

http://www.activeautowerke.com/exhau...us-SP-Gen3.asp

The muffler doesn't give much more, it's getting rid of the cat that gives the most gain on THIS vehicle and opens the flow.

Putting just a new muffler on a 4Runner will only give you 2-5 hp, it's more for a better sound than anything. Removing the cats would definitely give you more, but until a dyno is done, we won't know how great a yeild it will be.

 

The V6 is a LEV vehicle which is pretty amazing for a 4200 lb, 245hp 4x4.
In the whole "tread lightly" attitude, I think it would be best to try and minimize the environmental impact we all make. In the V8, im sure it's clean burning too.

That doesn't mean don't buy suv's- it just means I am happy that Toyota is doing it's best to minimize the environmental damage cars in general make.

I don't think it's a good idea to undo that for little if any HP gain. Also, what are you doing to your torque curve? Usually opening up the exhaust will kill your bottom end torque right?

just something to think about.

 

Don't remove the converter, it is highly illegal in all states.
If you sell the car to someone in that condition they can even turn around and sue you!

There is no reason you can't get full vehicle performance with the converter on. If you do think it is a problem you can temporarily remove it to diagnose the condition but if the converter is bad then buy another one and replace it.

 

Jason B-

I stand corrected... albeit very impressed. I knew that M3's were higher compression, but I never guessed that removing the cat's would net that much power... max gain is right @ 15hp... wow. The cat's must be pretty damn restrictive on those models... I doubt that it's that restrictive on the 4Runners though... Not restrictive enough for me to risk the potential $5000 fine (in NC) if it were my 4Runner. That much green will buy a nice TRD S/C.


J

 

Yea, and it's also illegal here in PA, but he did it anyway. He's knows a guy who owns a body shop who will inspect it for him. If you have a friend like that, you won't have to swap the cat back ON every year.

 

I always though removing cat. convs. what a white-trash, mullet-wearer practice. Guess I'm just ignorant