Corsa Xtreme Exhaust issue

[BW_in_RI]

Good morning,

I tried searching on the forum but found no prior threads. Just installed a Corsa Xtreme Exhaust on my 2024 5BW and man, it sounds AMAZING. However, shortly after (next day), the MyCadillac app threw two eerie messages, 1 for VVT and the other for ECU. Has anyone had issues with this? If so, what is causing it and what is the solution?

I attached images of what is going on.

Your input is greatly appreciated!

 

[jbawden]

You didn't say anything about the car, is it indicating these issues? If not, these alerts will likely go away on the app. The app sometimes needs to be refreshed. Also, if you've had other Cadillac products in the past or currently have them, that can cause issues too.

 

[RKS]

I'm am not mechanically-inclined but that sounds like an O2 sensor issue. Also, I think there are steps that you need to take with the exhaust valves before changing the exhaust. These ECUs are really picky.

 

[Sully]

Are you throwing CEL/codes?

The above “issues” aren’t informative enough to even begin a diag. If you have access to a OBD scanner, or borrow one at Autozone, to obtain the specifics codes, would be a good first step.

As mentioned, some folks may need to perform a relearn on the valves post-install. This may be a result of the valves orientation when shutoff prior to install. (I switched mine to Tour prior, disconnected battery, no errors post)

 

[BW_in_RI]

Thank you all for your input. I am only getting a check engine light and the aforementioned app alerts. Is it possible that it is a sensor disconnect? I am a first time Cadillac owner so any input would be greatly appreciated. I have a service scheduled this Friday so I will try and get my exhaust installer (highly reputable, probably the best in RI) to look at it closely tomorrow.

 

[Sully]

Thank you all for your input. I am only getting a check engine light and the aforementioned app alerts. Is it possible that it is a sensor disconnect? I am a first time Cadillac owner so any input would be greatly appreciated. I have a service scheduled this Friday so I will try and get my exhaust installer (highly reputable, probably the best in RI) to look at it closely tomorrow.

Theres only two electrical components that needs to be disconnected and connected during the install and that’s the valve actuators. All of the O2 sensors are before and after the cats but aren’t touched during the cat-back install unless you did headers as well.

Need a code scanner my dude, only way to really narrow in on the issue.

 

[Exia]

If its after the install get in touch with Corsa on how to fix the issues. Most likely something very simple.

 

[BW_in_RI]

I emailed them prior to Christmas but suspect they are closed for the holidays.

Is it worth taking my car to Cadillac dealer to get them to address the problem or go back to the original exhaust installer? Seems kinda risky to run the car with CEL and VVT/emissions ECU issue.

Thank you all for your help!

 

[piranha971]

I think the dealer is going to tell you to remove the exhaust before they work on it. And you already know that the issue is most likely exhaust related, so I don't see how the dealer is going to resolve it. They will be happy a few hundred dollars from you to tell you to remove the aftermarket exhaust though. I wouldn't worry about these codes until I resolve it. Give Corsa a call instead of waiting for their email response. From what I saw on there, the exhaust does throw codes.

 

[BW_in_RI]

Theres only two electrical components that needs to be disconnected and connected during the install and that’s the valve actuators. All of the O2 sensors are before and after the cats but aren’t touched during the cat-back install unless you did headers as well.

Need a code scanner my dude, only way to really narrow in on the issue.

Hey Sully, does the code scanner from AutoZone have OMDB-2 capability? Thank you!

 

[Sully]

Hey Sully, does the code scanner from AutoZone have OMDB-2 capability? Thank you!

Yes.. or grab a cheap code reader from Amazon or Harbor Freight, it'll pay dividend for ya.

 

[BW_in_RI]

Okay great thank you so much! I wrote airport code for Dubai Airport instead of OBD …

BTW, when you said Tour mode before, did you mean the drive mode as in the control knob on the right of the steering wheel?

 

[Sully]

I have a 6MT, my "Drive Mode" button is bottom right of my stick shift knob. The switch at the 4 o'clock on the steering wheel is the PTM switch for changing up the traction management. I think the DMC button for drive mode on autos is forward of the gear selector, but that's based on memory and my memory sucks.

 

[BW_in_RI]

No, you’re right. I also have 6MT. I’ll try that. Maybe a simple battery disconnect might do the trick. I had my exhaust guy shut off the CEL and it lasted a grand total of 2 days . I’ll get the codes and call Corsa to figure it out. Thanks again, I really do appreciate it

 

[Sully]

Many of the C8 owners use this bidirectional scanner for their exhaust relearns, pretty sure it’ll work just fine for the BW (this model is for GM vehicles). Only $129 after discount code. The dealer will prob charge $100 to press a button for ya..this way at least you have a great tool for future troubleshooting. My scanner is about ~$400 or so and it takes longer to navigate to the relearn option in the UI then it takes to execute the relearn process. I’m pretty sure Corsa is gonna tell ya the same thing.. eg you need to do a valve relearn (assuming that’s the issue at play here)

Amazon.com

 

[5VBW Nick]

From what you are saying it sounds like the exhaust valve thinks it is in one position when it is actually in another. This result is from when the car is turned off in one mode and then started back up with the valve in a different position from what it was at when it came out of the old exhaust. Clearing the code won't do anything, it definitely would need to be plugged in and relearn the exhaust valve position. It basically just recalibrates it to let it know what's closed and what is open.

 

[BW_in_RI]

So how would you do this? The Corsa instructions state to turn the valve actuator bracket to the fully open position prior to installing the spring from the factory valve actuator. My exhaust mechanic isn’t sure if the valves were open or closed when he took the factory exhaust off.

 

[5VBW Nick]

So how would you do this? The Corsa instructions state to turn the valve actuator bracket to the fully open position prior to installing the spring from the factory valve actuator. My exhaust mechanic isn’t sure if the valves were open or closed when he took the factory exhaust off.

At this point just need to plug in an OBD scanner with the correct functionality and do a relearn of the valves.

 

[BW_in_RI]

Ahh I understand now. Got it, thank you!

 

[Sully]

Assuming the valve spring which connects the valve to the actuator was installed in the correct orientation (Corsa provides a picture of the orientation in their install doc) then the only thing left to do is execute the relearn process.

The relearn process will trigger the valve actuator to full open and fully close, those voltage values will be registered into the vehicles ECM as %. From there, the car will know what % the valve should be at for different drive modes. Here are some screenshots from when I did this troubleshooting for another forum user.

Tour Mode, valve reads about 88% closed.


V-Mode, or for me, My Mode, shows about 11% closed (or "fully" open):


Without these values being properly registered into the ECM, the flow readings will not correlate correctly and will throw a code sensing an issue with the outflow. You will also notice that even in Tour mode, the valves will automatically open when you hit certain RPMs in different gears to allow for the correct amount of exhaust outflow to prevent bogging down the engine, this is all based on having a correct valve value baseline.

1. Buy the scanner above (or whatever one you want, just make sure its bidirectional), check codes, use Google-Fu to identify issue.
2. Execute the valve relearn process, takes literally seconds. Clear codes.
3. Take it for a spin, play with the modes, and if no codes come back then..
4. Drink a beer, celebrate, and issue yourself a certified internet mechanic title.

Again, this all assuming you have no other issues. Since you still haven't got the codes for your CEL then we're all shooting in the dark here.