no more Slow Down warnings

Disconnecting the ECUs is like taking your fire extinguisher out of the glass, empyting the fire extinguisher, and then putting the fire extinguisher back in its place.

BIG NO-NO!

Don't replace the other ECU just for the sake of replacing it. Replace only the one that is defective. They can be tested.

 

If you are running stock cats - you better have those ecu's working. They sense overheating cats which will lead to fire- no warning you gambling.
Or do what I did on my 348- install a pair of hyperflow cats, significantly reduces the chance of a cat related fire....

Those ECU's are very problematic, very common to falsely code.
Chris

 

Whether the catalysts being used are stock or not, the ECUs mustn't be disconnected. Hyper-Flow catalysts (or other improved catalysts) will burn up and melt just as quickly as the stock ones if the engine is sending a fuel mixture through the catalysts that is too rich.

 

What about disconnecting the ECU's and running test pipes/straight pipes?

 

I think to say that this is going to cause a fire is a bit of a stretch. I have never heard of any road car bursting into flames because the cat was too hot. That being said the converter may be damaged but it really does seem like a useless feature. I believe very few road cars actually have this feature. I think this is one area Lotus actually got right by not including.

Just my $.02 (and that does not buy as much has it use to!)

 

I put 20,000 miles on a 348 and so far 15000 on a 355 without those pain in the a$$ sensors without any problems. No other auto company that I am aware of uses or has used them. The concept is theoretically a great warning device(for the idiots that don't watch their CELs or take care of their cars) but they never seem to work correctly. I have heard stories over the years that in the rare case of a over hot cat that they didn't come on(I can't imagine in those cases the CELs didn't come on 1st, never heard either way). Of course they come on quite often when there is nothing wrong. If the system worked correctly I wouldn't be complaining.
The way the other sensors are used to send info to the ECU you are going to get a CEL if the engine isn't running correctly, ie; overly lean or rich and the 02 will trigger the light, malfunctioning 02 triggers the light, out of parameter fuel mixture and timing from the pre programmed maps will trigger the CEL, plugged up cat will trigger the light on the 5.2 cars etc. there are just too many other malfunctions that will trigger the CEL before that malfunction can cause the cat to overheat and trigger the cat light(slow down light). Except for one, the idiot behind the wheel keeps driving when the CEL(not the slow down light) comes on. So maybe this is Ferraris way of spreading socialism to the auto industry,ie; government protecting ourselves from ourselves being idiots.
They build somewhere around 11 million new cars a year in the US alone and know one else uses this concept. I have driven BMWs and Audis well past 120,000.00 miles with the same Bosch ECUs and never had a cat melt down.
I say pull 'em and take care of your car and watch the CELs like you would in any other car you own.

 

Though they can be a pain in the butt, I think it is unwise to remove a safety device. I have had to deal with catalyst ECU issues, and got through them. I would keep the system functional.

 

The ignorance displayed here amazes me.

Anyone who knows the first thing about Ferraris will say that it would be absolutely asinine to disconnect the catalyzer ECUs.

For those who would disconnect them instead of paying a few dollars to fix the situation, good for you. The system can and will work properly after some kind of effort is put forth first by the owner and second by a competent and knowledgeable Ferrari technician.

 

If one cannot imediately replace a bad cat ECU................. one can at least put the 'bad' ECU thermocouple in the bypass valve position...... where it will see only 'part-time' use ....... that way the two main 'failure prone' cats are still being monitored .........

 

Lets see... my oil level warning light comes on so I disconnect the sensor. No more problem, right? Same analogy here...

 

I had this problem last year on my 1990 348 TS. Start it up and drive it. After a few miles one bank would shut down. After a few more miles it would come back on and be OK the rest of the day. Mysteriously this year it has not happened after a long winter storage. But this year I had the ABS light come on and eventually go off and the check engine light come on and eventually go off on a long drive (over 100 miles) this last weekend. Maybe just take it out and drive it a significant distance and see if it clears up. Driving on one bank is no problem. You do not have much HP but you can keep up with traffic on the freeway.

Last year I found that if one bank went out I just shut the car off and restarted it and it went away. You may find things like this also.

Rodney Dickman
1990 348 TS

 

that's what would happen to my 90ts. the light would flash sometimes, sometimes it would stay on, sometimes it would
shut the bank down. It was like a crap shoot driving it if it would screw up or not.
There was never anything wrong with the way the car was running. It was just that ECU.
Look at the ECUs if they have that black epoxy junk in them I'd suspect the part.
btw, they're more than a few bucks to replace... can't remember but there are two different parts
depending on year one is less than the other, but neither are a few bucks.
I swapped sides to make sure I was trouble shooting the right part.

I think the cat is there just to be somewhat "green" otherwise it's pretty much useless.
Actually I take that back, I had a Maserati once that attempted to burn itself down due to
one, and a Jaguar xj that the cat glowed red once before having to have it towed.
So I guess they aren't that useless, they let you know when the car isn't running right.

 

Ah, but remember the OP has a 348, no bypass valve. Your solution only works for a 355, and even then, only in some cases. BTW, on the recommendation of my local dealer, I tried this, and it has been working fine for over a month now. Dealer says a "bad" cat ecu can often times work in the bypass valve application indefinitely, as the operating parameters are not nearly so stringent. But sometimes this swap does not work...always worth a try. He said worse case, you get a "check engine" light for a bypass valve issue, and you will know you must need to swap out the cat ecu in that position.

 

I have had a single episode of flashing slow down light on my 355, which is certainly faulty as I have test pipes. I pulled both ECUs, and both were cracked as has been described here. I will say I got a permanent flashing slow down light with them unplugged. I used silicone and resealed the casing of both ECUs and reinstalled them. We'll see how that holds up.

This is not a bad system, but it sure is a bad execution. The casing on those ECUs is complete rubbish, and they are expensive to boot.

BTW, I would argue that if you are running test pipes, the ECUs are completely useless, and have the ability to shut down half or all of your motor. I think this is reason enough to consider removing them, at least from a 355 lacking cats.

 

LOL... I love this site always someone available to entice to shoot their mouth off. You are awfully dramatic when a simple I disagree would do, Brahahahaha. Do you even know why Ferrari uses this system? Removing them for me has nothing to do with saving money($ should never be an issue when owning one of these machines) and I wouldn't have removed mine if they were a little more full proof. After doing some extensive research into the Bosch Motronic and how it works and Ferraris reason for the temp probes I decided they were of no value to me if they were going to interrupt the engine running for no reason other than their own malfunction. I think you need to check your own ignorance there Dave, oops sorry for being a little over dramatic!!

 

+100 ... Classic.

Robb