I currently installed a fi exhaust catback system on my 2019 coupe, the next morning i went to start it and noticed the rear exhaust valves do not follow the cold start sequence the valves go from the open position to closed and stay closed

•The valves do work when the exhaust button is pressed from the cabin
•valves open when the car rpm increases
•i have a simulator connected for the middle valve
•i have had the car scanned and no faults found

The valves just wont open how they normally would during cold start

Has anyone came across this same issue or know what the issue may be?

 

You can certainly bypass the valves with various products - Renntech works perfectly, etc. (which is what I did, now they stay open always - so much nicer)

 

Not trying to bypass the valves as i want them to work, i want to know why they are playing up

 

only time valves will not do startup procedure is if the flaps were disconnected and they have not been plugged in....... or valves and springs installed incorrectly/in reverse or flap settings was touched by a tuner......

who installed exhaust?? ur tuner??