I started this thread in another section and later realized this may be the more appropriate one. On my 456 I get the engine slow down light when I go past 90 or so and I stay there for a while. If I slow down a bit the light goes away. I speed up and it comes up again. This happens on one bank only. Any ideas or suggetions ?
Cat temp sensor issue. Could be the sensor, the cat, or a mixture issue on one bank. put the tester on and you should be able to get a fault read out. PM me for more help if required.
I dont know much about your model. But if its like the 348,355,f40 I would swap the exhust ecu's(there is one for each bank), very simple job, 5mins max. If the problem goes to your other side. then this is the faulty part. Very common, as water gets inside and freaks the eletric's out. report back.
What he said. Since you said that you are only getting the light on one side you could try swapping the Cat Temp ECU's from one side to the other. Then if the light jumps sides you'll know that it's the Cat Temp ECU that's bad. On 348's it is a VERY common problem, and most of the time it's the cat ecu. However, you could also have a faulty thermocouple. But try the cat ecu swap first and see how that goes.
