DIY OEM catalytic converter replacement?

Hey. If you have found a good or new HCAC cat system, good on you! You're lucky.

The reason I went to a modification to fool the vacuum sensor for the HCAC was because the dealerships I went to all confirmed that the part is discontinued and not available, and all the used ones I found were very questionable.

Except for having to warm up the car longer in cold winter weather before driving it, my non-HCAC system works as it should.

I am working on an idea to assist in preheating the cat on cold weather starts without the HCAC, and will post about it if it works.

 

You should certainly be able to handle this as DIY, plus sell the OEM cats for quite a chuck of money just for scrap price. The Gen 1 cats are about as valuable as the Gen 2.

 

A parts guy at Olathe Toyota told me that lately they've been getting them in about one month after ordered. If I understood correctly, he said there is new production getting spread around all dealerships by allocation for specific firm paid orders.

 

If you have the new OEM cat converter pipe, then the trickiest bit will be moving the HCAC actuator from the old assembly to the new one.
Your Dremel with a cutting wheel is your friend, here.
The bolts that hold that HCAC assembly are probably rusted beyond use. The parts 17520 and 17523 need to be transferred; they're not included in the purchase of 17410.
Replace any hardware with stainless steel, if you can.
(link to parts diagram: https://parts.toyota.com/images/parts/toyotaOEM/fullsize/a1_172502B.jpg. )
Treat yourself to a new set of gaskets,too (Walker 31690, front; Walker 31689, rear). They're available from RockAuto.
Maybe also a new spring/bolt set on both ends, too (Walker 36454, 2 sets).
The rubber hose which connects directly to the HCAC actuator may also need replacement. A 6 inch (150mm) length of 7/64" (6mm) black rubber hose from the local auto parts store will do, if the old bit of rubber is dried out or cracking.
I see that you're in Wisconsin, a high-salt state. I suggest a couple cans of Rustoleum High-Heat silver paint on the new parts to give them some additional protection against salt.
Operational hints:
Liquid Wrench, WD-40/PB Blaster are your friends.
For install, getting pressure on the forward spring bolts AND getting them to turn into their threads it tough to do by hand.
I use a drill with a hex-to-square converter plus a couple 3/8" extensions and a deep 14mm socket to get the bolts started.
Getting the bolts out is fairly easy, once the rust gets pushed out of the way. Getting new back in against the spring force is hard.
Extracting the O2 sensor from the old cat may be painful (after 20+ years in place); be prepared for a struggle, or buy a new O2 sensor.
To disconnect the old O2 sensor inside the car, remove the passenger side door kick panels and roll back the rug.
The O2 sensor cable disconnects and passes through a rubber fitting through the floor.
You will probably need a small screwdriver to depress the actuator which locks the connectors together. My fingers are too big.

 

This is correct. I just received mine today from Olathe, after ordering (and paying for) it on October 25.

I'm still trying to figure out what else I need other than the main Cat assembly. My original cat was stolen, including the HCAC actuator. In addition to the main Cat assembly, I have ordered part numbers 17230-21010 (Actuator Assy, W/Bracket) and part 17338-21010 (Spring, Air Control) from the diagram. I know I will also need the rear O2 sensor.

What are the parts 17520 and 17523 described in the quote above? I see 17523 on the linked diagram. This part is listed online as "PROTECTOR, EXHAUST PIPE, UPPER NO. 3", but is shown as "discontinued" on the various parts sites. I live in Southern California, so if this part is just to keep the actuator dry, I could probably omit it or improvise something. I don't see 17520 on the diagram, and my googling didn't find any part 17520 that seems to make sense for this application. Perhaps @dabard051 meant 17230, not 17520?

Any help or guidance would really be appreciated.

 

jakob, DaveGoodRich, here is the list of official Toyota parts names and numbers from ToyotaPartsDeal.com:
Exhaust Pipe - 2002 Toyota Prius
The hard-to-find items are the OEM cat converter assembly ($$$$) and HCAC actuator ($$$).
All the parts listed as item 17410 (in the diagram) are included when you get the OEM cat pipe assembly.
The rest are highly likely available from RockAuto, although I haven't checked recently.
BTW, I find the RockAuto site helpful in figuring out what parts are needed for a job, too.

 

Thanks. I was able to order the cat assembly and the HCAC actuator, and yes they were $$$$. I have also been able to order part # 17338, which is listed as a "Spring, Air Control."

But I can't seem to find a source for part # 17523 which is listed online as "PROTECTOR, EXHAUST PIPE, UPPER NO. 3", but is shown as "discontinued" on the various Toyota parts sites. This looks like it is a cover/shield for the actuator. Any ideas for a source? If not, I think I will just try to improvise some kind of sheet metal shield to protect the actuator. Not sure what I am protecting it from however. Heat, flying debris, etc.? Again, any help would be greatly appreciated.

EDIT: found part 17523 on ebay. Price was reasonable, shipping doubled it.

 

The hcac protector shield 17523-21010 is hard to find. It's been discontinued. Will the hcac be ok if the shield is omitted?

Also curious if it can be installed later without dropping the exhaust (if I find one later).

 

No probs. That was my thought as well. I think Toyota discontinued it since it was not providing too much value / cost. I ended up installing w/o it.

The actuator is between the 2 cats above the pipe and it's shielded from the bottom.

 

If the heat shield is below the cat (if I’m reading right), it might be there to to reduce risk of starting a fire, say if you park over tinder dry grass?

 

There is a shield below the 1st cat, attached (after the exhaust flange). But there is a another u shaped shield underneath the actuator to shield it from the pipe and the 2 cats. You can see from this pic