p0420 code at 60,000 miles??

I have a 2008 Prius. It now has 98,000 miles and a Po420 code, but it had ~60,000 when I first got a code (I assume it was the same code, but never got it read). I live in NM now. I was living in CA when I first got the code, but it was running fine, I didn't need a smog check (smog check for Prius not required in CA), and the dealer was going to charge $100 to diagnose it. At the time I thought it was a faulty intermittent CEL since I think I had had a faulty intermittent code before on that car, didn't realize an autoparts store could check the code for free, and didn't realize the catalytic converter (cat) would be under warranty. Water under the bridge.

When I moved to NM 7 months ago, I needed a smog check to register my car. I googled and found I would probably need a $2000 cat, and put off doing anything about it til now. Dealer diagnosed last week ($100) and told me I needed a cat. ($2200), a mechanic then diagnosed ($60) and said I could use a Walker direct fit cat. ($900). Then I went to Midas and they said they would diagnose for free and use a universal cat. (if it can be fit to it) for $430.

The car has run well the entire time, and gets ~45 mpg.

1. What are the cops likely to do if they pull me over and find that my car is not registered in either CA or NM?
2. Which of these cats. would be likely to clear my code and enable me to pass the smog test? Will they do anything for me if it doesn't clear the code/enable me to pass the smog test, or am I out the money and back to square 1?
3. Does the cat. failing (most likely) at 60,000 miles indicate that something else is likely to go wrong (such as the cat. failing again) even after I replace the cat.? If so, should I just get a new car? I have been thinking about a cmax energi plug-in hybrid, which I can afford, but I don't like to waste $36K if I don't have to.

Thanks in advance.

 

Did you install these on Prius Gen II's?
If so, does it replace the front or rear converter?
Do I need to replace both?

Thanks. And thanks to Patrick too for your response.

 

Thanks. When I took it to Midas, at first they quoted me for a universal cat. and asked me to come back and get a free diagnosis to make sure the cat was the problem and to see if the universal cat would fit. When I came back they confirmed it was the cat, but told me the universal they had quoted me wouldn't fit and that there were 2 cats in the car. They then quoted me the Walker direct (which presumably wouldreplace both cats) for $750.

Does it sound like Midas don't know what they are doing and that I shouldn't get the work done there? Or is it hard to screw up the work of bolting in a direct cat? Does the direct cat replace the (one) cat and both resonators all the way back to the back bolts? I didn't like the mechanic (I'm new in town and don't know any mechanics) I took it to that quoted me $900 on the direct cat, so I am not going to give them the work. I don't plan on keeping the car that long (although I may change my mind on that), I just want to pass the emissions and give myself a year or two until the next test. I wouldn't mind saving the money on a universal cat, but I don't want to spend much more time and energy on this problem if I can get away with it.

Any other advice would be much appreciated.

 

I ordered the magnaflow cat from ebay. I'll keep everyone posted as to how it turns out.

 

I got the Magnaflow cat. recommended. Went to a Midas to have them install it and they quoted $240. I went to a small garage next door and they said $200. I said, I was told it should be $50-100. The guy said 'ok, I'll do it for $100'. Took it back to Midas and told them they would do it next door for $100 and they said that once it was up on the rack, they would tell me it would cost more than $100 at the other place. Then I took it to Meineke and they said $220. This was Saturday and I wanted to make sure to get it done that day, so I let them do it.
Drove 100 miles that weekend. CEL still off. Came back to Meineke on Monday to get the OBD and they said two readiness monitors still incomplete. Drove about 40 more miles, then yesterday at Meineke they said 2 readiness monitors still incomplete, but they told me if I took it to a certain emissions tester they would pass me. I did and they did.
Thanks everyone for the advice. I hope the new cat will last me longer than I keep the car (probably less than a year or 2).