Mustang GT350 Forums banner
1 - 6 of 6 Posts

· Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Basically, I can change between exhaust modes in neutral and there is a very noticeable audible difference. As soon I fully release the clutch into gear it gets MUCH quieter. I can change between exhaust modes using the switch while driving but it doesn't make it sound any different at all. The valves are still opening when I apply more than 50% throttle.

It's weird, like as soon as I release the clutch, the exhaust goes into normal mode despite the dash still saying it's in sport mode.

I would appreciate any tips or advice on how to try and fix this.
 

· Registered
2019 GT350 Shadow Black/White Stripes
Joined
·
155 Posts
You didn't supply any info about the car like year, mileage, and whether you've done any modifications?
Without knowing more info, it sounds like some sort of electrical problem. Even a dying battery could cause problems.
 

· Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
You didn't supply any info about the car like year, mileage, and whether you've done any modifications?
Without knowing more info, it sounds like some sort of electrical problem. Even a dying battery could cause problems.
Sorry, I completely forgot.

2017 GT350, 6000 miles. recently purchased from a Ford dealership that assured me it was stock. I realized yesterday that it has what looks like Mustang Stainless headers.
Everything else worked 100% perfect but this issue has been going on since I got it. I didn't realize it in the test drive since it was my first time driving one of these cars.
 

· Registered
Joined
·
47 Posts
There is a wiring harness attached to each individual actuator for the actuator blade within the exhaust pipe. The 2020+ GT500's have an issue with the harnesses rubbing against a sharp-edged body panel and it eventually causes a shorting issue. I have not checked my 2019 GT350 actuator harnesses yet to see if they are in close proximity to said sharp edged panel, like the GT500. If they are, you can cover the harness to protect it from chaffing. If the shorting harness is the issue the harness can be replaced by a technician. On the 2022 GT500 the fuse number 34 is usually blown as well. It's under the hood on the GT500. Also, it's best to do this on a lift as the exhaust system has to be dropped to access the harness.
 

· Registered
Joined
·
4 Posts
Discussion Starter · #5 ·
There is a wiring harness attached to each individual actuator for the actuator blade within the exhaust pipe. The 2020+ GT500's have an issue with the harnesses rubbing against a sharp-edged body panel and it eventually causes a shorting issue. I have not checked my 2019 GT350 actuator harnesses yet to see if they are in close proximity to said sharp edged panel, like the GT500. If they are, you can cover the harness to protect it from chaffing. If the shorting harness is the issue the harness can be replaced by a technician. On the 2022 GT500 the fuse number 34 is usually blown as well. It's under the hood on the GT500. Also, it's best to do this on a lift as the exhaust system has to be dropped to access the harness.
That's very interesting. I kind of assumed that it wasn't a wiring issue since the valve control works perfectly in neutral, but resets to normal mode when I release the clutch. I'm not well-versed in electrical issues so I'll probably have a dealership look at that.

Is this something that could be caused by the car being tuned? The dealership told me that the car has never been tuned, but since they didn't disclose the car having headers they might have lied about that too. Not sure why someone would want to tune the car to disable sport mode though...
 

· Registered
Joined
·
47 Posts
That's very interesting. I kind of assumed that it wasn't a wiring issue since the valve control works perfectly in neutral, but resets to normal mode when I release the clutch. I'm not well-versed in electrical issues so I'll probably have a dealership look at that.

Is this something that could be caused by the car being tuned? The dealership told me that the car has never been tuned, but since they didn't disclose the car having headers they might have lied about that too. Not sure why someone would want to tune the car to disable sport mode though...
I would doubt a tune causes the actuator issues. The GT500 owners complain of intermittent actuator behavior which is probably due to the beginning of the wire damage shorts. It finally just stops working.
 
1 - 6 of 6 Posts
Top