Maketrax

I've had my new to me 2012 C2s for a couple of days. It doesn't seem like the PSE is working though. There is no noticeable change in exhaust sound when pressing the sport exhaust button. Exhaust sound is fairly mellow so I'd guess it's stuck with the PSE disengaged. I did find one post on here from 2013 saying a faulty change over valve could be the culprit. Any other ideas? All change over valves were supposedly replaced (could have failed again) a few years back with campaign C43 (?). When pushing the button without the engine running I can hear a click coming from the rear of the car so it does seem that it is trying to actuate the valve.

Very happy with this car. I'm planning to drive it for the next couple of weeks and note any abnormals before taking it in for the 4year service.

This potential PSE problem is all I've noticed so far. What an amazing car!

Jabs1542

If you lay on your back and look underneath the rear of your car you can see the valves (someone posted a picture of this somewhere). You could probably watch the valves move if you had someone inside the car to flip the switch. Note, I would use a mirror on the floor if the engine is running.

Usually a faulty change over valve throws an engine code and you get a notification on the MFD.

Maketrax

I guess that's what baffles me with this. How noticeable is the change in exhaust sound when sitting at idle and actuating the button? I did a YouTube search and it definitely seems noticeable even when stopped and idling. Thanks. I'll go check and see if I can see the valves actuate.

Maketrax

Just checked and neither valve moves with the button. I can manually actuate both and open the valves for a noticable change in exhaust note.

Someone also mentioned this could be caused by a vacuum line that has come loose. Anyone know where this would be located?

John 996 TT Cab

on my 991S X51 I have very little sound change at idle but once moving WOW. My Macan Turbo changes sound level substantially (or so it seems) even at idle.

clutchplate

Are you just pushing the sport exhaust button? On mine there's no change unless I push the sport button which activates sport mode and PSE. Then it's loud.

Larry Cable

time to visit your local mech I think - or return to the seller/dealer for a fix my guess is that the location of the line is not easily DIY accessible

https://rennlist.com/forums/991/800240-ongoing-change-over-valve-issues-on-991-a.html

Maketrax

I've tried both.

ezdriver

You gotta take it out for a ride and step on the gas. I don't hear much of a difference when in idle but when I step on the gas .... its is awesome. Trust me ... you will hear the difference ... unless the windows are up and you have iPhone headphones on.

Maketrax

I think you're right. I did find a thread on 6speed talking about a vacuum line coming loose s the culprit.

Jabs1542

I agree with Larry, the line isn't easily accessible and something you probably want the dealership to fully check out anyway.

BTW - Some people purposely disconnect, and tie off, the vacuum line to force the valves in one of the two positions. Tieing off the line prevents the fault codes.

Larry Cable

even at idle and in normal (vs sport or sport+ if you have Sport Chrono) pushing the PSE button should open the exhaust flaps and you should hear
a definite change in exhaust note ...

if you also position yourself at the back of the car and have someone operate the PSE you should hear the actuators open and close ...

since you have already identified that you can operate them manually and can
hear a difference in note, clearly the system is non-functional ... the rest is a
simple matter of finding the fault and repairing it DIY or otherwise.

Larry Cable

given you probably have to either remove the back bumper and/or jack the
car to access the engine compartment - I think in the absence of a DIY thread
this is a job for a professional!

Jabs1542

Yea I'm wondering if the previous owner had them tied off.

Larry Cable

highly likely; probably fastest way to tell is to pop an ammeter across the connectors to see if current is applied to the actuator, if it is then its got to
be a vacuum problem ...