F355 2.7 with CEL 1-4 & Slow Down 1-4

I'm sure the circuit inside is pretty much the same, but the connectors are completely different. The good news is the ECU for the 355 is one third the price of the 348, if that turns out to be your issue.

 

Green tend to be more reliable, but can still fail, ask me how I learned this...

 

Oh great now you've done it. FNA will be raising the prices now.

 

Anything I can do to help, lol! To be fair to FNA, it was when Ferrari turned the parts biz for the 348 (and older models) over to Ferrari UK that we saw parts prices go through the roof.

 

Update...I shined a flashlight inside my Hyperflow Cats today just out of curiousity and was a bit dismayed to see the right side matrix was completely coming apart. The right side was the side that threw the CEL and Slow Down. There was also some molten pieces of matrix stuck to the end of the temp probe. We stuck a mirror in the Capristo exhaust to see if any damage had been done downstream as well and all appeared to be fine.

The left cat matrix was still 'together' but was loose inside.

Opinions on what to do next? Replace both cats right away? Would there be any kind of coverage from Hyperflow/mfg on these units. Doesn't seem quite right that they should be disintegrating like this.
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I would suspect that Hyperflow will want CO and HC measurements pre-cat to show the engine is not causing this. You will want this as well, to assure you the engine is running properly.

 

Yeah, pretty much. Head mechanic at the shop called and spoke to Hyperflow and they're fairly convinced that the engine did this (ran too rich for whatever reason).

Interesting when the head mechanic mentioned I had just completed putting the Gold Connector Kit on the car, the Hyperflow person was very pleased to hear that and remarked "If I ever bought a 355, I would not turn the key before installing that kit". I suspect that we'll get the car all back together and testing it and find no trace of what led to this result...thanks to the upgraded connectors.

Anyway, I've already decided to go ahead and replace the cats. Hyperflow apparently tests these things up to 2,500dF before they disintegrate and normal temps are maybe ~1000dF - so clearly this is not a game I want to be playing.

 

Rick, looks like you need new cats right away, so this may not work for you. I contacted a non-sponsoring vendor in Newport Beach who supplies hi-flow cats to the NSX crowd on NSXprime.com. I think he has jigs to make cats for both the Motronic 2.7 and 5.2 cars. I spoke to him on the phone today and he uses a 200 cell US made cat, but would not tell me if it is a Random Technologies, Carsound (aka Magnaflow) or other catalyst. I already bought new manifolds from Ricambi for my car and I'm thinking of using these cats plus a Y-pipe cat-delete.

Anyways, his retail pricing on the pair is $1695, but he has none in stock. They are build-to-order right now. If you are interested, let me know and I'll see if he'll cut us a deal for 2 sets.

 

It does look like it got overheated - if there is a silver lining, it is that the cat ate it and not anything further upstream. Save your old cats as these can be re-cored legally (even in Cali!) or you can hollow them out for use on track days...

 

My car is a 1995 355 Spider 2.7 and when I failed emissions testing last year I took my car to a mechanic. My oem right cat was completely hollowed out. Looked like an empty tin can. I purchased a replacement oem cat to pass emissions and then the first thing I did was pull both working cats off and replace them with test pipes. At least with test pipes you don't have to ever worry about the ceramic cat material disintegrating again and damaging either your engine or exhaust. Test pipes sound amazing, shoot fire between gear changes at high RPM and are easy to install yourself. I only paid $450 for a pair of test pipes on ebay.

To address your original problem, I also had my slow down 1-4 light come on and it was the cat ecu. The Black are the old style and the green the newer replacement from Ricambi. This also is a cheap and easy fix by Ferrari standards. Good luck, hope she is back on the road soon!

 

Yeah, if you ever want them to get to your car, I need a solution right away. LOL. If I'm going to put cats on, I'm sticking with the Hyperflows for better or for worse.

Ahhh, always putting ideas in my head Mr. 3forty8! Where could I get them re-cored?

Yeah, I think my Cat ECU is actually ok. I do believe it was trying to tell me something now that I discovered what was happening with the Cats. With the gold connectors now on and a fresh major ... we shall see if it throws anymore codes.

I like the idea of just getting test pipes...who can resist the lure of shooting flames?!?!

Perhaps I could just gut the Hyperflow cats and use them as test-pipes? When it comes time to smog the car, I guess I would need some cheap cats to throw on there in order to pass.

 

Swap the 1-4 with the 5-8 cat temp ECU to make sure it works. When mine went out on my car it was not related to the bad cat that I had to replace. Here is the link to the test pipes I have on my car.

http://cgi.ebay.com/ebaymotors/Ferrari-95-99-F355-2-7-5-2-High-Flow-Cat-Test-Pipes-355-_W0QQcmdZViewItemQQhashZitem2c57c2ae93QQitemZ190450937491QQptZRaceQ5fCarQ5fParts
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Troy (HyperFlow) invested a good deal of time and energy on the flow bench while devoloping the Cats for these cars, it is a wise move sticking with them. Others may look the same but rest assured they do not flow the same.

 

Yep, did that ECU swap a couple weeks ago and drove it for a week. The problem did not recur on either bank. I think I mentioned it an earlier post.

Yeah, I'm convinced they've got the best engineered part.

Question d'jour is whether I should replace the units or just gut them and run them as psuedo test-pipes.

The advantage to gutting them is that I can monitor for the situation that led to the break-down of the core while not risking damaging a brand new set of cats.

 

Just curious how many miles on your Hyperflows before they went bad? Most 1995 355's run lean compared to other years. This could be causing your problem.

 

They were put on in 2007 by previous owner...maybe 5-7,000 miles ago max.

Hard to say when the cats started going bad...I've not noticed any tell-tale rattling but maybe it was like this when I got it last December.

 

If you replace the cats I would make sure your bypass valve is operating correctly. If it doesn't that could contribute to the failure of the primary cats.

 

Thanks James. I just got off the phone with the head mechanic and we discussed the same thing. I'm hopeful that there is at least a partial easy fix here - not only for my aural pleasure (as you know, I'm getting inconsistent sound out of my Capristo at WOT) but also for the premature failure of the cats.

BTW, we tested the bypass valve the other day for a vacuum leak - and there was none. Will continue to chase this and the entire system though to make sure it is all operating correctly.

 

Picky I know but new owners might misunderstand... They didnt go bad, a malfunction up stream, likely in the engine management caused them to fail.

A Cat has no ability to change what it is fed, its a completely dumb component. Feed it unburnt fuel beyond what it was designed to deal with from low compression, bad headers, bad engine management, poor injectors..... and it will fail.

Doesnt matter if its a 2.5, 2.7, 5.2 or a 7.3, feed the HF Cats what they are supposed to get and they will outlive any reasonable expectations, read many tens of thousands of miles.

 

Thanks Dave, this is good info.

 

There are sampling ports on the (oem) exhaust manifolds for each cylinder. You really need to find out your CO and HC readings pre-cat before doing anything else.

 

Yep, that's the plan...will let you all know what I find out.

 

Run lean? What data do you have?...Here is mine and it shows rich..never even got close to 14:7 AFR on this 95 2.7.

Definitely follow f355spider's post. Just because you've done work on this engine doesn't mean you've solved the problem that led to the cat failure.
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You are correct, I meant to say rich, sorry.