Codes P0420 and P1436

This is for code P1436
This works good & cost less than a new exhaust system 'LOL' . I found that if I didn't check the vacuum of when the valve starts moving I may not have fixed it & have to do it again. so I take a brake bleed vacuum pump and make sure that it starts moving at less than 5 inches. 10 inches wont do it. One of these I had to take a small hammer and just tap on it for over an hour, along with moving it back and forth, to get it free to less than 5 inches of vacuum. This may seem to be overkill but it is still less than $1000 or more as in some of the previous post. If it is totally stuck, It may give you a no start companion code also and you have to take the key all the way out for 6 times and try to restart and it will usually restart. There may be a time delay on this also to purge the exhaust . Once you fix the valve you won't have the no start problem again.

 

So a little clarification would be appreciated. Can anyone confirm or answer any of the following...
1. If the valve is stuck open, and you live in a location without emissions testing, their is no detrimental effect to not fixing this other than a small decrease in efficiency?
2. If the valve is stuck closed, then car does not function properly
3. Their is no sensor on the valve itself. The sensor MUST be somewhere in the vacuum mechanism powering the valve.
4. Which position is open, and which is closed? In layman terms... If lever is pulled to the front of the car, the valve is... ?open? If lever is pulled to the back of the car, the valve is ?Closed?
5. Does anyone see any reason why the arm from the vacuum control cannot simply be removed from the valve, and allowed to move freely?
6. Any issues with this valve not functioning in Extreme Cold weather - 0 F for instance? Assuming longer for engine to warm up, but should not affect starting???

I have just purchased an 01 prius, excited as I new it only had 50,000 on new hybrid battery. Now this. Not willing to spend $1800, which is dealer quote. Valve is severely impeded at this point. Car would rarely be more than 30 minutes from home. Planning on some experimenting before I give up, but the P1436 light - along with check engine and error screen on the LCD on the dash - are permanent at this point. Resetting codes cleared it for a few days, but now will not reset.

Thanks