Scuderia SLOW DOWN light

If you are getting a red Slow down lamp (not amber) you are overheating the catalysts so they are obviously still working. Simply installing new or different catalysts will not correct the issue. You must first find out the cause of the overheating or you will simply destroy the next set. Many times this is a false warning due to a failed sensor rather then a truly overheating catalyst.

 

Many times a poor connection or ground can cause the system to read a false high. This is easily tested when the car is cold at room temperature and it is common to see one read 150-200 degrees rather then room temperature. During normal driving this does not cause a problem but once you push it you can get a false warning.

It needs to be properly diagnosed before throwing parts at it. If the cat is truly overheating there is a cause, the engine is not running properly. A properly running engine will not cause the catalysts to overheat.
Are you running pump fuel at 91-92 octane? Unleaded Racing fuel can cause overheating issues.

 

keeping in mind Europe uses a different calculation method than the US, I hope it is unleaded, 100 octane may cause your issue. Higher octane burns slower and can cause exhaust temps to rise. I would strongly advise you try 92 octane and I suspect your concern may very well be resolved.

An engine can still feels like it is running well but have high emissions causing high exhaust temperatures as well.

You either have a false reading or a overheating exhaust and simply swapping out catalysts will not fix either issue.

 

Why do you put fuel with such high octanes in your scud when even ferrari claims best at 95oct? I rarely put 98 and mostly use 95 which is best. Cheers

 

I had a similar issue on my F430. The left side exhaust temperature post cat probe was reading 1300 degrees! The temperature probe was replaced and the problem went away.

 

Yes, a thermo couple. This little sod in fact ...
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Never heard of cats being replaced at such low milage....a friend of mines has over 100'000 km on his scud and cats are still perfect. IMHO 100 octane fuel is too high for the Scud.

 

Sounds like the exact problem I had with the "slow down light"

Don't know if it's like my 360, but on my 360 there are two green box sensors, one on each side of the engine. They are located under the engine panels. I would check those first, in fact it's an easy DIY. It's the part that the sensor plugs into. I think it's called the Cat ECU.

If you have a reader, you can find out which side of the engine is tripping the light. From your description, I would guess electrical too as it doesn't appear the car is going into "safe mode" and killing a bank. Anyway, if you know what side of the engine is causing the light, just switch the boxes. If it happens on the other side then you know it's the computer/ecu.

I spent much mechanics time trying to find this problem and got the same answer you did. Not an expensive fix here in the states as the part is like $500 and you can do it yourself. Check my profile for my detail on this. They are problematic and prone to fail.

 

Does this problem only occur when using the high octane fuel?

Does this problem only occur when running the car hard on track?

The most common causes for this warning light are

1. Faulty thermocouple
2. Misfire (faulty plug / coil / other)

Have you determined that one or other of the Cats actually is overheating? Can you see it glow brightly in the dark?

If not actually overheating it's probably the thermocouple.

 

Good advice! Something that might help diagnose, which I take to the track with me:

Amprobe IR-730 Infrared Thermometer, -26F to 2282F, 30:1: Science Lab Digital Thermometers: Amazon.com: Home Improvement

They have cheaper ones also, but the range is not as good. Obviously many options out there. Also good for checking tires, brakes, etc.

 

You really need to determine whether this is a false alarm or not. The IR gun will be a good investment and has many uses. A quick look under the engine hood at night time will also be very effective but less scientific. Faults in the temperature sensing hardware are common on the 360s, a little less so on the 430 but as the fleet ages ........

If it is a misfire you would probably feel/hear it in the performance of the car so I lean towards a false alarm, probably as a result of bad thermocouple.

Do check though, if they are overheating they are damaging themselves and perhaps are also a fire risk for the car.

 

Sadly I am not totally familiar with the full workings of the Scud but..... check out the diagram linked below and specifically item #19, of which there are two ...

Ferrari 430 Scuderia Parts : Table 18 - RACING EXHAUST SYSTEM

I wonder is he perhaps looking at Nut #5 and gasket #4 and mistakenly thinking that is where the thermocouple ought to be? There's normally the likes of what you describe for the purpose of gas analysis.