Installed Torque and I think I need a new Catalytic Converter.

Why do you think that you need a new catalytic converter (AKA catalyst, or cat). Your catalyst temperature at 1180F looks like its a bit high. Is it always that high?

Have you received any DTC codes?

If so, what are they?

 

I will compare cat temps on my Torque app and let you know what I am experiencing. That way you will have a better baseline.

 

See my previous posting, which also applies to second-generation Prius cars.

I wouldn’t replace any parts unless there are drivability problems, smoke or odors, or a current diagnostic trouble code (DTC). The engine control module is designed, as required by emissions regulations, to continually monitor the sensors, and to store a DTC and turn on the Check Engine light if it detects a malfunction.

 

Fully warmed up (185F coolant temp), I found that the temp for catalyst temp1 was in the 950F to 1000F range on a 77F relatively cool July morning.

 

I wouldn't be replacing any parts, on any car, based on readings from Torque. No codes, so apparently the car doesn't think it's a problem. Before I threw a ton of money at something, spend a hundred bucks and get techstream and a laptop. At least then you'll know the info is accurate and you'll have a lot better equipment for troubleshooting any other issues down the road.

 

You can find it everywhere. AV gets disabled because it interferes and kills the sample rate communication with the car. How well would you do if you could speak only one word per minute. If you're worried about it, buy an older laptop and have it dedicated to TS, with wireless disabled.

Older laptops are available all over craigslist, letgo, ebay, etc. I have one version of TS on my daily use computer and another on a dedicated Win7 32 bit computer.

You don't want to spend a little money on having TS but you're ok with installing a replacement cat and O2 sensor without even knowing if it needs to be replaced?

Use google to learn what causes cat system to get excessively hot and what doesn't. Then think about the fact that techstream can look at, monitor and display live data and every single information point in existence on the car, whether the car is running or not.

or don't.

 

Then buy a small SSD for about $50 and load Windows XP, if you have your old CD (or buy one for $20 from Ebay if you don't). Then swap that drive into your laptop when you want to run Techstream.

 

Not trying to be a jerk. Trying to help you not throw a bunch of money away on something that may be completely normal or may not be the root cause of your problem, but maybe I'm coming across wrong. So let's start over.

From the original post: I don't know what temperature the CAT is supposed to run at, but I don't think this is right at all. I did several runs, and it stays around this level.

So I use Google to search "what is the normal temperature for a catalytic converter?" and it gives me this:

what is normal temperature for a catalytic converter - Google Search

So according to this, your temperatures are in the normal range. Now, are they in the 'normal' range for a Gen 2 Prius? Other posters threw some numbers up for comparison. Are they being measured under identical circumstances? idk, so let's just say yours are on the high end.

So now I use Google to search "what makes a catalytic converter too hot?" and it gives me this:

what makes a catalytic converter too hot - Google Search

You have a very high quality Toyota OEM cat system on your car that is very expensive. You think you may have a problem with it but have no DTC for it or for anything that could lead to it. A cat system, on its own, doesn't just decide to go bad one day. Something external to the cat causes a cat to act stupid or fail. If you do have an "unrecognized" problem with the car that is currently causing excess cat temps (with the oem cat), I would imagine a $200 replacement cat wouldn't handle it nearly as well, or maybe it would handle it great, since it's probably has 10% of the catalyst that an OEM contains..

Now, if you want to buy a direct swap/direct bolt-in $250 cat system and install it ahead of time to ward off thieves, that makes sense to me. Keep the oem one in case you need to put it back in for inspection or sell it on ebay and come out $500 ahead on the deal.

Also keep in mind, that the first cat is tucked up near the exhaust manifold out of the air stream. The second converter is at the same level under the car as the resonator and is directly in the airflow stream under the car. Neither of the cats has a direct reading temperature sensor located on it. There is merely an air/fuel ratio sensor in the exhaust manifold and an O2 sensor in the pipe about halfway between the 2 cats.

Techstream will allow you to look at the sensor values and also has a live test you can perform to verify the sensors are reacting as they should. You can also look at and test fuel trims. And mass air flow, and spark/misfires. It has hundreds of tests that can be performed to verify proper system responses.