Update! It's definitely time to ditch the 3 stage manifold now. My large DISA failed/shorted out/caught on fire today in a drive thru. Still smelling the lovely smell of an electrical fire. Tons of smoke from the DISA valve even when the car is in accessory mode. Not related to the PCV heater, tried running the car with the PCV heater disconnected and still had smoke from the inner DISA.
For additional information, I installed brand new OEM DISA valves from FCP Euro at the time I installed the 3 stage manifold. It was at 55k miles. So I've been running that manifold with no issues for 3 years and 30k miles now.
N54 manifold time, I guess!
