CC260 that's the beastie, though I never pulled mine that far apart. Not quite sure I understand your question, "Does the membrne still resist?" I'll ass-u-me you mean does it resist the increase in pressure? As there's all of a 11% change if I hit Stu's numbers, I'll take a wag that it's ok. I've never had one apart & hope to never need to. People who have, tell me they look simple but never worked quite the same after re-assembly. The lower pressure is constantly being changed as the system regulates mixture anyway. Both the inner arm of the flapper and the ECU's duty cycle sent to the EHA are making changes constantly.
mctwin2kman Excellent!!
I stayed with the single 1/4 turn CW adjustment on the EHA, but needed a 1/8 screw turn CCW on the idle CO adjustment on the flapper arm to offset it once it warmed up. That was pretty subtle. I've GOT to rig up a way to read out duty cycle & maybe even O2 sensor voltage inside the car while driving it.