348 running on one bank

The limp home mode doesn't shut of cylinders it just means that the ECUs are using different sensors to compensate for the one not reading correctly ie; if the air flow sensor quits for some reason the ECU will use the TPS readings instead. The Cadillac system you are refering to is an economy concept they came up with to save fuel at certain engine load levels. The engine ECU would shut down 2 or 4 cyclinders to save fuel. Chrysler is using a similar system on thier hemi.

As I said above I think it has great merits it just doesn't work and instead of spend $600 over and over to fix something that doesnt work, I chose to remove it.

IIRC someone on here even said they had a cat overheat one time and the ECU didn't even react the problem, go figure works when its not supposed to and doesn't when you need it to.

 

Okay I wanna call BS on the whole cat catching fire myth. Yes the cat can get so hot that is can cause a fire. But here is why I call BS.

For the last couple of years I have been running my 348 with the cat ecu's disconnected. Last year I couldn't get my car to pass smog by just 0.1. Well when I pulled my trany I had to take the exhaust off and I found out why I could pass smog. The right side cat was EMPTY. The cats only had about 6,000 miles on them. The left side cat was just fine, but the right side was completely gone. Keep in mind that the cats on my car are the ceramic type.

Now if the cat got SO HOT that it completely burned out the material, THAT should have been hot enough to cause a fire. Well guess what, NO fire. The only thing that was lost was the insides of the cat. Since the inside of the cat is now gone there is NOTHING to get hot.

What caused my cat to burn up, was a misfire that I had been plagued with and couldn't find for many months. If there was going to be a fire I surely would have had one. But instead the cat took the punishment.

I have heard of Ferrari catching fire from busted fuel filler lines, but I have yet to hear of a Ferrari catching fire from an over heated cat, or ANY car for that matter. Not that it couldn't happen, I just have never heard of it.

 

You may be right, but how do we know "how much" fuel it would take to cause cats to catch on fire?

One bad spark plug? Two? 3? 4?

Can you just pour gasoline into the center of a hot cat and have no fire?

Where's the limit, with some fuel being safe/no-fire and more fuel than that causing fires?

From personal experience, I've watched a Porsche burn up in front of my own eyes when it leaked automatic transmission fluid onto its 1986 cat.

 

We could debate this until I'm blue in the face so let me see here I'll solve the problem for you. You keep your temp probes in place and me and Ernie won't, how's that? Hahaha. Regards, Vern
Oh.. I almost forgot how is the temp probe concept going to help that porsche(if it had the system) from splilling auto fluid and catching on fire?.

 

I can't see the cat temp probe concept being of much help to Porsche...so I suspect that they didn't use it.

Now, as for our Ferrari cat temp probes, to me it's not the probes or the warning "SLOW DOWN" lights that are the complaint...but rather owners don't appreciate the automatic shutdown of 1 bank of cylinders.

Well, that's the part to disconnect if you're of that mindset. Keep the warning light system, but ditch the shutoff (it's just one wire to one pin on each engine A/F ecu).

 

On the "owner appreciation" thing I'm not sure what you mean?? What's to appreciate, the system doesn't work. As for using the system light only for a warning? As I said above it doesn't always come on either. On my car the offending bank was shut down, no light no hot cat nothin'. So even if you can/could disconnect the " injector shut down" part you still don't have a full proof system for a something that rarely ever happens(over heated cat) Maybe you should wire this wonderful system into your other cars that have cats. Hahaha
Again don't get me wrong I think the concept is an interesting idea but it just doesn't work in Ferraris case. As I have said before the problem it is supposed to watch rarely happens which is probably why no one else in the auto industry uses it. Regards, vern

 

Okay, since you swapped the Cat ECU's and still get the problem on the same side, I'm gonna say that you have a screwy thermocouple on the right side.

I don't think you need to swap the thermocouples because you already swapped the cat ecu's and the right side still lit up. If you like you can swap the thermo's and see what that does. But I'm gonna guess that you either get the light on the left or it goes away.

The other thing is, have you pulled the engine codes yet? If not you should pull them.

 

Hey ernie, can he simply measure the resistance on the two wires from the thermocouple? Less than 10 ohms when cold equals short/problem??

But what I don't understand is why a bank would be shutdown by an exhaust ecu without lighting up the SLOW DOWN light...if the problem is the thermocouple or exhaust ecu.

...especially if the problem waits until the engine is warm.

 

Instead of swapping them around just unplug the ECUs from the main engine ECU for now and then run the car again, simple test.
ND as I said before those lights don't always come on even when there is a malfunctioning part(ecu or probe) you would think it should but that's the prob. I had, shut down bank no lights(shruging shoulders HaHa)Regards, Vern

 

He could have bulbs that are burned out, or just plain removed altogether. He would have to pull the instrument pod and have a look. I would guess the later. When I first got my 348 it would give me slow down lights but no check engine. Can you guess why I wasn't getting the check engine lights? .................Pull the pod.

 

Have you checked the ignition side-to-side yet? Sounds like a lot of time on the cats for no result.

 

There is an entire crop of dishonest sellers...in time the Internet is going to seriously crimp their style. No way can they get away with as much today as they were able to pull off in the past.

 

Ya know................before you pull the pod, do all the lights, seatbelt, slow down, check engine, break, etcetera, come on when you turn the key to the "on" position, but don't start the car? If they come on then your bulbs are good. If they don't, you know what to do.

 

Hi Ernie, I think he already did that see posts 8 and 9. Vern

 

Thanks for the follow up, and congrats to your service guys for nailing the problem.

 

You have right it is not possible that the engine shut down without SLOW DOWN light if is over heating. To test if your pb is coming from the thermocouple,disconnect it and drive your car with the SLOW DOWN light and you will see if the car shut down.