DIY catalytic converter replacement/shield removal

Hello all! My uncle lives in Minneapolis and has had his cat stolen 3 times now from his 2008, so he's over it and is looking to get rid of the vehicle. I'm in Wyoming where 1) These thefts are not really a problem and 2) there is no inspection for registration, so I'm hoping that I'll have better luck out here. Unfortunately, I need to do the repairs in MN away from my garage to get it out to WY in the first place.

I'm looking for advice on fixes that won't require welding, and also part numbers if anyone has them.

The hitch: my uncle had a cat shield installed after the second theft, making it hard to see exactly what was removed. He says there is an approximately 33inch gap in the exhaust (they cut on either side of the shield)
-Does anyone know if this means more parts than usual have been removed? Is the upstream O2 sensor still safe? I haven't owned the vehicle and can't get eyes on it so I'm flying blind right now.
-Had anyone had experience removing these shields/cutting through them? Seems like it could be a PITA to try to work on the car with it still installed.

Any tips/part numbers/links to repair videos/diagrams of the exhaust system etc. would be greatly appreciated!

 

If it's helpful for anyone...

The shield was a pain to get off with a hacksaw, drill and crowbar. Would recommend an angle grinder, honestly. I thought I might be able to slide the new cat in while leaving the shield on but it didn't turn out to be feasible.

The thief had cut at the manifold and right before the resonator, but I was hoping to avoid taking it to a shop to weld, so I ended up buying the whole exhaust from manifold to muffler (Eastern Catalytic 40712) on Rock Auto. This part says the gasket to the muffler is not included but it came with one anyways which I ended up using. The manifold gasket included with the part didn't seem to have as snug of a fit as the original, which was still in good condition, so I reused the original. I also bought four exhaust bolts because I wasn't sure about the condition of the originals, but the ones I bought (Walker 36454) didn't have tapered tips and did not seem to tighten down as well, so again, I re-used the originals.

The Eastern Catalytic assembly, unfortunately, comes in two pieces (the cat and the resonator/pipe) with a U-bolt exhaust clamp. Maybe I screwed up the exhaust clamp, but I couldn't get a good seal with it (loud, low mpg) so I ended up taking it to an exhaust shop and having them weld it for $50 anyways. Were I to do it again, I'd just get the Walker cat and have a shop weld the joint. Of course, the Walker cat was out of stock when I was doing all this...

The (downstream) O2 sensor, of course, was missing so I got the Denso 2344623 (234-4623). Cleared the codes just fine and they haven't come back.

Overall, a pretty easy job and well worth it. I'm loving my new Prius.

 

ydpplqdb, I'm not sure I would go with a generic cat for pure DIY, based on my failed experience with exhaust clamps. But I've been pleasantly surprised with how cheap my exhaust shop has been, for both welding that joint on my prius and building a new/custom exhaust for a 1990 toy motor home that I have.

 

Hey Jonathan. Hope this isn't too late. I had the work done at Laramie Tire and Auto. But I should note that I already had the new cat fully installed, I was just having them weld a joint that I had exhaust clamped. If your Magnaflow is not attached to the car yet, that's probably why you're getting higher quotes.