Reduced exhaust volume with open valves

[spyrosd]

Hi everyone,

I am getting a decreased and somewhat muffled exhaust note even though valves are open (in both sport and track modes). It's noticeable on cold start and on downshift blips, as well as medium acceleration past 3k. The valves look open to me (photos below, track mode), but as the car is new to me am not entirely sure whether this is the full open position. The change in exhaust note started after a three day track weekend at Watkins Glen.

Grateful for any advice or guidance.

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[Mach VII]

Both sides sound reduced? Maybe piece of cat substrate broke off and is wedged somewhere?

 

[NightmareMoon]

Did you remember to take your helmet off after the track day?

 

[NMoore]

Both sides sound reduced? Maybe piece of cat substrate broke off and is wedged somewhere?

That was my guess - clogged / compromised cats.

 

[spyrosd]

Did you remember to take your helmet off after the track day?

That’s it - I knew I forgot something !

 

[spyrosd]

That was my guess - clogged / compromised cats.

Is there an easy fix other than taking apart the cats ?

 

[NMoore]

Is there an easy fix other than taking apart the cats ?

You might be able to remove the upstream or downstream O2 sensors, and put a borescope in to visually inspect the condition of the cats or look for any obstruction in the system.

 

[sukhoi_584th]

I'd be careful when giving a cat a colonoscopy

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