sandcrawler

$297.00?!

cootees

That was a direct-fit converter. I checked my Magnaflow and Eastern books and they do not list a direct-fit cat or a suggested universal cat for the highlander. If someone can give me the measurements of the converter body and inlet/outlet diamater size then I may be able to match up a universal cat for pretty cheap.

If you do a froogle search then the typical going rate for the direct-fit cat for the highlander starts at $275+. Link

msw0085

search ebay: performance peddler

Back40

They only list one for a V6. Unfortantely my wife's Highlander is the 4banger which they do not carry. Thanks for the link though.

FastCat

If your state doesn't require emissions testing, I would simply not worry about the cats. Ya, there are those that think you would be polluting the air, but really, EFI engines today run so clean that practically the only time a catless engine would fail an emissions sniffer test is on a cold startup where engines are usually programmed to run rich, or during open-loop (at WOT).

If you feel you must install a cat, then just get the least expensive one that will fit your vehicle, unless you are into hi-performance and need a hi-flow cat. I'm kind of new to Toyota maintenance, so I don't know which type of cat Toyota uses, but a cat is a cat. They all do the same thing, so there's no reason to prefer a more expensive one over a less expensive one.

rimpainter.com

Just match your pipe diameter to an ebay Magnaflow special, such as this. Since you are a 4-banger, your pipe diameter might be 2" (check on that). But you get the idea. Expect to drop around $80 at a place like Midas to install it.

$641 is ridiculous.

cootees

On the other hand. Since his vehicle is OBDII if he goes catless then his CEL will come on and stay on. Some people do not mind that... It would drive me insane. If something were to go wrong later on and he didn't have a CEL to come on and alert him of it, there is a possibility that he would never know until it is too late. Thats just my .02

FastCat

Is there an aftermarket O2 sim product out for Toyotas? The post-cat O2 sensors are not used for closed-loop engine control, but merely to check that the cats are working.

O2 sims would keep the computer thinking the cats are good, keeping the check engine light off.

But ya, forgot about the post-cat O2 sensors.

droppdwn

Guys, I'm currently living overseas in Armenia. The gas here is pretty sketchy (read: leaded) and I want to remove the single cat from my '96 4Runner. I'd LOVE to keep my lowend torque (I'm running 285/75s and a mild lift), does anyone know if I could drop in a 2" pipe to replace space where the cat was? I think my cat back is 2.5", but might be 2.25". Would that bump up my back pressure more than just running straight 2.5" pipe to replace the cat?

I'd love to avoid my check engine light being on all the time, but I don't see how I can avoid it with multiple O2 sensors in place...

thanks

MTL_4runner

I don't agree with the first part. EFI engines are cleaner burning than carb'd motors but nowhere near as clean as when running a cat. EFI motors (with no cat) can definately put out significant emissions even when warmed up.

I do however agree with the second part more or less. There are a few converter designs but for the most part all of the high performance aftermarket cats use a honeycomb design which works very well for flow and emission reduction.

It is very poor mechanical practice not to replace a malfunctioning catalytic converter.

....I am curious what the OBD codes was to replace the cat....if it was P0420 then that is not always a bad converter.

MTL_4runner

Wow, leaded gas!

Man, that must just wreak havok on just about any vehicle made today. You can remove the cat, but again you'll have a constant CEL. That is about the only circumstance I could possibly think of that would require removal of the converter. I also worry about what other damage you'll do to the motor. I think the stock pipe is 2.25" so if you stretched a 2" pipe on both ends (to mate to the 2.25"), that should give you some back pressure. Very tough to say.

If I were in your shoes I'd probably get a diesel 4runner instead.

cootees

Yes. 02 Simulator


Placing a test pipe in place of your cat will reduce your back pressure.

That is true to an extent. The two most common materials that a cat is made out of is a ceramic brick and a metallic brick. The metallic bricks are more on the pricey side but they will last longer and hold up better against melting, breaking, etc... As far as high flow cats go.. 95% of all aftermarket cats are high flow compared to OEM standards. Now there are real high flow cats but they will cost more than your typical $50-60 "high flow" cat.

Unless the lifespan of your cat has passed then it is rare that a cat will just go bad, most of the time when a cat goes bad before its lifespan is up it is caused by an improper running engine.

I hope my ranting helps someone.

Back40

Actually I am getting 6 OBD codes:
P0420 - Catalyst system efficiency below threshold
P0430 - Catalyst system efficiency below threshold bank2
P0440 - EVAP Control System
P0441 - EVAP Control System Improper purge flow
P0446 - EVAP Control System vent
P0161 - Heated Oxygen Sensor Circuit - BAnk 2 Sensor 2

Thinking about taking it in to the dealer and hope he's honest with me about what the problem(s) are, then go from there.

I really appreciate everyones feedback!

FastCat

Just FYI, codes P0420, P0430, are probably caused by P0161. IOW, it appears you have a bad post-cat O2 sensor, and it's making your computer think your Cat isn't working correctly anymore.

The EVAP codes sounds like you might have a leaky gas cap seal or vapor hose from the gas tank, which is common. Finding exactly where it is can be a real pain, but it might be obvious too.

Back40

Thanks FastCat. Hope you're right and all I need to replace is an O2 sensor. Are aftermarket O2 sensors as good as stock? That is if I can find aftermarket.

One more question. What does the bank 2 mean? I have not crawled under the Highlander so I am guessing there are 2 post cat O2 sensors. I know there are 2 pre cat in the exhaust manifold.

Thanks again....Ralph

MTL_4runner

Usually there is 1 or 2 banks of O2 sensors on a vehicle, most of the time there is one bank per side on a V type motor (V6 or V8, etc). Some vehicles like a 3rd gen 4runner with a V6 will only have 1 bank (even though there are two banks on the motor). So if you see a code like bank 1, sensor 1 than would mean that the O2 sensor in front of the cat is malfunctioning and it is obvious because there are only (2) O2 sensors total. If you see an error like bank 2, sensor 2 that would mean the sensor after the cat is malfunctioning (you need to contact the dealer to see which side of the enigne is considered bank 2 for a Highlander) because that means there are (4) O2 sensors on that vehicle.

Best way to verify if you need a cat or not is to look at the waveform of the O2 sensors after the cat with an OBD tool.

FastCat

Technically that's very true. Mostly that is when the motor is running in open-loop mode, where the computer isn't reading the O2 sensors to control the amount of fuel delivered. That is when the engine has just started cold, or when it is at WOT. In closed-loop mode though, the amount of elevated emissions usually still isn't enough to fail an emissions test.

That's what I said, was that you can still pass an emission's sniffer test even without cats if the engine is warmed up. I've watched it happen and was surprised.