Good - high flow, non-OE catalytic converters?

[CBR.worm]

Just yesterday as I was wondering if my Infiniti FX45 (V8) was built any better than the M and G series for towing and general truck type use (the way I use it). I had the cruise control set on the highway, when I started heading up a hill, the tranny downshifted and I noticed a gray cloud appear between me and the trailer. I let off and the cloud went away, got on the gas again - gray cloud back. My first thought was tranny or head gasket. I have worried since day one about the long term durability of this engine/transmission combo, although I have had zero issues up to this point.

I pulled over and verified that if I revved it, a gray cloud came out from behind the car - so definitely not the tranny, I didn't smell anything sweet and it didn't look like steam. The front of the trailer had a strange gray dust and the exhaust tips were also gray. Underneath the car it sounded like broken glass was rattling around at idle.

I drove the rest of the way home, unhooked the trailer and everything seems to be ok. I assume that one of my (4) cats just disintegrated. What I don't know is which one or why.

I am hoping that it is a post cat as the pre-cats are built into the exhaust manifold, and also potentially can let cat material into the engine causing mass destruction - a la early 2000's altimas.

I have 107K miles and am surprised that a cat let go this early, although I suspect the vehicle is probably not made for the amount of trailer towing that it get subjected to.

At this point there has not yet been a CEL. My journey the rest of the way home yesterday netted the same 10-11 mpg on the highway that I normally get with this load. I don't know if a chunk broke loose and dissolved and I should just ignore it, or if doom is soon to follow. I want to avoid causing more damage.

I have a few questions. The OE cats are ~$750 each online. I don't really want to pay that much unless they are better than the alternatives. And that is assuming it is the post cats. I don't know how to check for damage short of removing them, or possibly renting a FLIR camera.

There are 'OE Fit' cats that are available as well as universal replacements that can be welded in.

I would like to gain performance if possible, certainly I do not want to give up any by using a universal cat that does not flow as well as stock - I don't know if this is a real concern. It seems the direct fit and universal cats are all physically smaller than OE.

Are there any more reputable or less reputable companies I should be aware of? I keep seeing Eastern Catalytic popping up in searches. I also seem to be finding a lot of sites that have the same part numbers showing for the V6 and V8 models, although I am quite certain that they are different.

There are no emissions tests here, but I do want to keep cats on the vehicle.

Suggestions?

 

[Kool1]

I have used Magnaflow OE grade cats and in less than 10,000 miles had the check engine light come on in my CRV. This happened twice so I went back to a factory Honda cat which cost me over $1,000 and now have almost 30,000 miles on the Honda cat with no problems.

 

[NMBurb02]

Magnaflow? They offer a lot of aftermarket direct fit cats.

 

[OVERKILL]

I'd confirm it is in fact the cat before going any further. Should be able to pull the O2's and look in with a scope.

It may just be running rich.

 

[rslifkin]

I've had good luck with the magnaflow high flows on the Jeep (universal cats, as I don't have any stock exhaust parts left, save for the tip at the back). I had one on there for about 55k miles, no codes or other issues. I just pulled it and switched to a different shaped one when I re-did the exhaust. Random Technology makes some nice cats as well.

I'm with Overkill on this one, make sure there's nothing else going on before you start swapping cats.

 

[Wolf359]

According to Eastern Catalytic, the reason they're smaller is that they don't have to meet the original spec as the manufacturer, so they can make them smaller. They should keep your check engine light off which you don't even have on at this point. I would go for a direct fit, you'd probably run into more problems trying to make a universal one fit. The aftermarkets seemed much cheaper around $150 each, just make sure you need them before replacing them. Also the aftermarket ones do come with a warranty, I think Eastern Catalytic is 50k. I think federal emissions is 8 years/80k unless you're running a Pzev which I think can extend certain parts to 15/150k.

 

[SteveSRT8]

I have always found the aftermarket cats to be much less durable than OEM. But if there was an application specific product with a guarantee of OBDII compliance I might give them a shot.

Don't forget low mileage junkyard replacements...

 

[gofast182]

If you want a high-quality, high-flow aftermarket cat and the part number is the same as the for the VQ check out Berk Technology. They're among the best for high-performance replacements.

http://www.berktechnology.com/product/ni...ytic-converters

 

[Wolf359]

Originally Posted By: SteveSRT8
I have always found the aftermarket cats to be much less durable than OEM. But if there was an application specific product with a guarantee of OBDII compliance I might give them a shot.

Don't forget low mileage junkyard replacements...


For catalytic converters, you can't find them at a junkyard, they're illegal to sell, I think it's a 10k fine.

 

[SteveSRT8]

Originally Posted By: Wolf359
Originally Posted By: SteveSRT8
I have always found the aftermarket cats to be much less durable than OEM. But if there was an application specific product with a guarantee of OBDII compliance I might give them a shot.

Don't forget low mileage junkyard replacements...


For catalytic converters, you can't find them at a junkyard, they're illegal to sell, I think it's a 10k fine.



Ssssh, don't mention it out loud man! The EPA will hear you...

 

[djb]

Originally Posted By: Wolf359
Originally Posted By: SteveSRT8
I have always found the aftermarket cats to be much less durable than OEM. But if there was an application specific product with a guarantee of OBDII compliance I might give them a shot.

Don't forget low mileage junkyard replacements...


For catalytic converters, you can't find them at a junkyard, they're illegal to sell, I think it's a 10k fine.


They are both illegal to sell for reuse (some twisted logic there..), and profitable to sell for precious metal recovery. Merely being illegal wouldn't stop mistaken sales, but not making more money on the transaction does.

On Craigslist you'll sometime be able to buy complete exhaust systems, or mufflers with attached parts thrown in at no additional cost.

 

[JD4440]

I've used magnaflow universal hi flow cats with good results.

 

[Trav]

How much oil does this one use when being used for towing?

 

[CBR.worm]

Not too much. It uses a quart every couple thousand miles typically. I use M1 0w40 and change it about every 5-6K.

These are known to use more oil than what many would consider acceptable.

 

[Trav]

Thats not bad, it shouldn't have much impact on the cats. I have been using Eastern for aftermarket with decent luck.
Walker is ok if you use their Cal Cat, their "normal" line doesn't seem to hold up very well.

Personally on this car i would go OEM or empty cans (which you have, you didn't do it) with rear O2 extenders.
We did a lot of testing for the MA Emission program some years ago and found many cars passed on the dyno sans cat anyway.

 

[CBR.worm]

So I took everything apart tonight. The precats are fine, one of the post cats has lost all of its guts. The last o2 sensor is before the cat that has no guts, so I guess I can drive it as is. I don't know if there will be any imbalance having one side of the motor with 2 cats and one side with one. Maybe the other post cat will disintegrate as well.

I will watch the fuel trims which have always been very similar between the two banks, if they stray than I will figure out what to do next

Thanks for the input.

 

[jrustles]

Originally Posted By: gofast182
If you want a high-quality, high-flow aftermarket cat and the part number is the same as the for the VQ check out Berk Technology. They're among the best for high-performance replacements.

http://www.berktechnology.com/product/ni...ytic-converters


Wow, dangerous prices on the Berk units but I guess they're up there with Random Tech cats. I'm looking for a couple new cats muhself for a Supercharged Jag- apparently at least one bank is totally melted shut

 

[SteveSRT8]

In the LX community the Magnaflow cats are often installed as a high flow "improvement".

Most of them seem to fail. The reason is the pig rich mixture that the stock tune runs, especially if you have a heavy foot. No aftermarket part ever measures up to the R&D that the OEM's do routinely. Then there's the codes thrown, cloaking the O2 sensors in steel wool, etc.

Note that most modern cars gain very little from exhaust mods without professional dyno tuning except noise. Even tuned it is an extremely minor gain, usually less than 5-7%, as the exhaust is already tuned by the OEM.

 

[dailydriver]

Originally Posted By: Kool1
I have used Magnaflow OE grade cats and in less than 10,000 miles had the check engine light come on in my CRV. This happened twice so I went back to a factory Honda cat which cost me over $1,000 and now have almost 30,000 miles on the Honda cat with no problems.


Were the Magnaflows absolutely the C.A.R.B. certified versions, or the '49 State' variety?

I know that my car came from the factory as a C.A.R.B. certified, LEV, so when owners try to use the 49 state catcons (Magniflow or otherwise), they WILL (eventually) get an SES dash light, and codes set, due to the much more sensitive O2 differential reading written into the ECMs of these LEV cars, and the much thinner 'precious metal' content coatings of the 49 state catcons.