F355 spyder capristo

What cats do you have if any.
Lots of info we dont have about your car and check the search function, sdl are very common. I get one once in a while even on a cold start and my cats are gutted. Its so many different things up.to and includding the actaul purpose for the sdl and thats a over heated catylitic converter that is dangerously hot. Almost 1800 degrees.

 

Keep the Cap, I’ve had mine for 11 years and it’s never caused a light. Also stock exhaust is a much more muted sound.

 

as a 1999 it has the third Thermocoupler at the bypass inlet of the exhaust.. potential chance the capristo fitted to your car does not have the thermo bung at the bypass.
therefore that thermocoupler is just hanging somewhere and can cause the SDL to come on..

as a result by driving it hard as you said.. the bypass is open regularly.
that thermocoupler is not getting any readings and throws the SDL.

otherwise the carpristo properly fitted will not throw the SDL..

 

One of two things is true:

1) Your SDL system (thermocouplers, wiring and ECUs) are working properly and you have a CAT overheating.
2) Something is off with either the SDL thermocouplers, wiring or ECUs

History on this forum probably would put the odds at 8 to 1 that you have an intermittent problem with SDL system. That said, if you have a Bank running rich it will heat a CAT up to the point it will trigger a SDL. The best way to tell is to get a IR temp gun and check that CAT temps on both sides when the light comes on. In short order you will know if the system is working properly.

I don't see the Capristo as part of this problem unless as Tony mentioned it was not properly installed.

 

take the cappy off - will give you loads of hassle! sound is also overrated..............!!

(PS PM me - I'm looking to buy a good used Capristo!