BadBrainDay

Assuming the BOV itself is in good shape, it should work fine. The HKS BOVs are very well made, including the older ones. I used one similar to the above, but it had a plastic housing. It was still working great at least up to 20 psi with no leaking at idle until the day I replaced it. That was on a DSM. In fact, the older HKS BOVs have a better sound (in my opinion), without as much of the "chirping" in the current Super Sequential. That retaining ring is called a snap ring or a circlip. You'll find it much easier to get it in and out with a set of pliers specific to that purpose ("Snap Ring Pliers"). You just compress the snap ring and wiggle it out.

The capacitors in the ECUs in these cars tend to fail over time, causing all manner of weird problems. I'd open up the ECU and see if there's any capacitor puke on the circuit board. See here: http://www.tmo.com/howto/ecu1g/caps.htm