Should I buy a catalytic converter or sell my 2004 Prius?

I have a 2004 Prius with 96,500 miles on it. I have taken great care of it with regular maintenance. The check engine light went on so I took it to the dealer. They told me that I need a new catalytic converter at the cost of $2,100 for parts and labor. Should I have this repair or should I give up on this car and buy a new one? If I get a new catalytic converter, how long will my car last after that? How long do these cars last?

What was the code? Have you replaced the oxygen sensor(s)? Many things set off the light, usually not a converter.

How long do these cars last? Our library director traded her 2004 in at 194K and still kicks herself for getting rid of it. Consumer Reports found one with 214K that only required tires, belts, etc. Apparently Prii will go for quite a while.

The code was “#P0420 Catalyst below efficiency.”

That can be caused by a bad O2 sensor I think. You might also ask this on priuschat.

cats are ofen miss dinosed i would get a second opion but not from a dealer

I’d get a second opinion, but if a second mechanic confirms it’s the catalytic converter, get a new one installed. Your car should be relatively trouble free for another 100,000 miles if you continue to take good care of it.

I agree with Whitey. Get a second opinion and then fix it. Although your car will probably need some other repairs in the next few years, this is still the economical choice.

Third vote,get other opinions and prices…this is not part of parallel drive and installing a cat on the gas motor should be within the capabilities of experienced mechanic. Yes, it is worth fixing. I would FIRST call Toyota customer service at the manufacturer and see if you can get help. Though over warranty, complaining in a nice way can help. This seems a little early for one to go.

Fourth vote here. I believe that roughly half of the catalytic converters replaced in this country work perfectly when diagnosed as bad.

I’d Replace The Catalytic Converter If It’s Bad. However, These Are Often Blamed For Other Problems That Can Trigger P0420 (One Of The Most Commonly Found Codes Causing A CEL Illumination).

The Car Isn’t Worth Much With A Check Engine Light On And A Bad Converter, But Has Some Value Again When It’s Put Right.

Although it is possible for a converter to go bad on its own, many people pay many dollars to replace a converter, only to have the CEL back on a short time later. 100,000 miles is an early death for a catalytic converter.

If, in deed, it’s really bad then one be certain to find any problem that could have contributed to its early demise. Not corrected, whatever killed that one will kill the new one, too. This requires a competent professional diagnostician.


On the other hand, my experiences seem to show that O2 sensors seem to last about 100,000 miles or a little less so I would look at this first. You are right at the life expectancy of this part. Has your mileage suffered at all?

Here’s an (edited for clarity) list of possible causes from for a P0420:

A code P0420 may mean that one or more of the following has happened:
1 Leaded fuel was used where unleaded was called for
2 A damaged or failed oxygen sensor
3 Downstream oxygen sensor wiring damaged or connected improperly
4 The engine coolant temperature sensor is not working properly
5 Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe
6 Retarded spark timing
7 The oxygen sensors in front and behind the converter are reporting too similar of readings
8 Leaking fuel injector or high fuel pressure
9 Cylinder misfire
10 Oil contamination

I’d SURE want to eliminate the other causes (many of which are either cheaper to fix, or will ruin a new converter) before replacing the converter.

+1 for @CSA. I couldn’t agree more.

For that price, you should get 3 or more written estimates. If you do ned a cat, look into an aftermarket catalytic converter if they are available. An OE unit might last another 9 years, just like this one. Will you keep it that long? An aftermarket unit might last a few less years, but it won’t be your problem if you sell it before the new one goes bad. And if you don’t replace it, your car is woth $2100 less than it is with the new catalytic converter. It still needs to be replaced.

My 2004 Prius is getting ready to turn over 200K and it’s great. Keep it going!

The most common cause of the P0420 in general is a leak in the exhaust before the rear sensor, but when it comes to a Toyota, the most common cause is the rear O2 sensor. You need to get the replacement sensor from a Toyota dealer based on the VIN number of the vehicle to make sure it is the correct one. This will probably run around $200 to $250 if done by the dealer. The dealer should know this, must be the service writer giving you the bad info and not the mechanic.

No matter what the problem, I always recommend ditching the car. So, keeping that in mind, you could try changing the forward O2 sensor because it’s cheaper than $2,100 dollars.

A lot of people who have followed my advice are enjoying long walks. Competent and professional are not the names of the streets on the corner where I live.

On the other hand, my experiences seem to show that O2 sensors seem to last about 100,000 miles or a little less so I would look at this first.

I’ve NEVER replaced one. A total of 6 vehicles (3 mine, 3 wifes) over the past 30+ years with a total of well over a million miles.

I’m hoping that, since the OP hasn’t posted since April 3, the issue is resolved by now.