355 replacement cats ?

I've just ordered a new set of Larini high flow cats. Not sure what they would cost landed in the USA. I've been told that the F355 Challenge Larini cats are suitable for road cars, although I'm not sure about California.

https://www.larinisystems.com/collection/ferrari/f355-challenge

I was also looking at Evoflow.

EVOFLOW


The Larini looked nicer and cheaper.

You'd have to ask owners what they sounded like.

Cheers
Ian

 

Just an observation.... cats and O2 sensors are downstream of all the fun stuff that happens in an internal combustion engine. Maybe the real problem you're facing originates further up the food chain.

 

(in no particular order).... cam timing, exhaust leak, intake leak, MAF, etc. etc. Honestly, I have no idea why you're getting a CEL; my point is simply that if you have a qualified mechanic with experience on the F355, let them do the legwork.

Do oxygen sensors fail? Sure. But lots of times, I think they're failing *because* they're suffering at the mercy of incorrect timing, inefficient cats, and so forth. Indeed, you could just keep replacing them periodically, or your mechanic can determine what is causing them (and I suppose your cats) to continue failing. I bet the original problem isn't your O2 sensors or cats; those are just the 'tail end' components which are reacting to other stuff.

 

Tony - you don't have any pending codes or hard codes yet you have a CEL? That does not make sense....

If your CAT's are failing, you will get a catalytic efficiency code as detected by the post CAT O2 sensor.

So I would not start replacing CAT's without a proper diagnosis.

When I replaced mine, I did speak with Glenn from Nouvalari and he stated they don't guarantee no catalytic efficiency codes with their hi-flow CAT's so I went with EvoFlow instead.

 

empty o2 spacers with no wool inside.. will eventually give you CEL..

take your current spacers off and stuff some wool in them and test..

if not.. get a set of Fabspeed minicat spacers..

im running them on my 5.2 car with a set of straight pipes.. and not a single CEL..!

 

You are not mentioning what codes you are getting. (if there is no code, you are shooting in the dark without a proper diagnosis) If they are for "low catalyst efficiency", the only real solution is to use factory catalysts. In my experience, all aftermarket catalysts will eventually start throwing CE codes for that. Those that never had this happen with aftermarket cats, just haven't had them on long enough. Spacers can help, but even that is no guarantee.

You want the latest oem version Ferrari made with the metal cores. The early ones (through 1998) were ceramic. What happens is the ceramic core works loose from the housing and starts moving/rolling around and crumbles apart (poor quality control, they otherwise worked fine). The metal core ones don't do that.

For whatever reason, the Motronic is super sensitive to catalyst efficiency on the 5.2 cars and the best, most trouble free solution is oem catalysts. I picked up replacements off Ebay....took about a year to find a pair (bought in separate transactions). One was brand new, the other lightly used. Just get the part numbers and set up an automatic search on Ebay to email you anytime there is a new listing.

 

I agree with this - perhaps I've not had my Evoflows long enough (not 2000 miles on them yet)
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This worked for me (90deg angled spacers) with *straight pipes*.

 

The primary reason everyone gets aftermarket catalysts is the oem ceramic ones fail, as I described. The oem metallic core ones are ridiculously expensive (ask Daniel at Ricambi ). But what is interesting, a couple times FNA has run "specials" on the metallic core catalysts through the dealer network, offering two catalysts installed for something like $2200. I recall 5 or 6 years ago, getting a call from Ferrari of Seattle explaining the promotion and telling me if I needed catalysts, this was a great opportunity. I was good at the time and passed...then I had issues later and started trying to find some (had already tried rebuilding one with a metallic core, and worked with a few buddies locally with 355s using Hyperflow and other brands...all caused CE lights). The new one I found on Ebay was from a guy who bought them on the promotion from a dealer, but never had them install one side, since it was still good. I think I paid him $500 or $600 for it.

 

the Cat efficiency code.. is because the o2 sensor is sniffing stronger gas/exhaust content then the parameter its set at..

if a car throws this code with stock cats on.. then yes may very well be a bad cat, or maybe a faulty sensor..

as soon you put Hyflow cats, the core is not srubbing the gas as much.. and very possible to get a cat efficiency CEL.

so that's where a spacer can and will correct that with steel wool in the spacer. with no wool the gas just passes through the spacer and throws CEL eventually.

as mentioned above, im running straight test pipes now, using the Fabspeed minicat spacers.. with not a single code, nothing.. that's it that's all..

im on my 7th exhaust configuration..in 2.5 seasons of ownership, so ive tested it all..!

the fact that OP is getting a CEL doesn't mean the Nouvalari cats are going bad.. it just means the sensor is doing its job and is detecting the stronger gases..
my recommendation to OP is to put steel wool in the spacers.. and run the car to test.. if the CEL still throws after that.. then its something else etc..

 

That could be a great tech article.

sjd

 

I did do a write up..

correction im on my 6th configuration.. my write up ended at the 5th.. and now im on my 6th setup..

i'll update to add the 6th setup..

my 7th setup... eventually will be to get a de-cated aftermarket y-pipe in there..

http://www.ferrarichat.com/forum/348-355-sponsored-bradan/535282-5-different-f355-exhaust-configurations.html

 

Cats. Hi-flow cats will do that.

 

The catastrophic converters store excess oxygen from the catalyzing process for later use, as needed. The oxygen sensor before the catastrophic converter will see higher levels of oxygen than the oxygen sensor after the cat. This indicates to the system that cat. efficiency is good. When the oxygen content hitting the 2nd/output cat. oxygen sensor starts approaching the oxygen measurement of the 1st/input cat. oxygen sensor this will trigger cat. low efficiency code. Assuming the oxygen sensors and associated circuitry are good then it is a real indication the cat. has deteriorated due to age/miles/contamination/damage. All these cause a reduction in the surface area where the catalyzing process takes places. So... maybe some of the sport cats. are freer-flowing (less restrictive) due to the fact there is less surface area for the catalyzing process to begin with???

 

Contact Glenn at Nouvalari - he told me for a 5.2 car they won't guarantee no CEL which is why I went with EvoFlow. Glenn was very nice and up front.

 

Definitely from the upgraded cats. If you don't use a proper core, you can easily trigger catalyst lights on the vehicle. P0420/0430 are usually triggered depending on which brand primary cats being used, or if factory converters start failing.

 

Yes.

 

For how long or how many miles?