2005 Prius - replacing catalytic converter at 85,000 miles

Do you know the actual codes that they pulled from your car? That might help with the assessment of whether the catalytic converter is actually bad or not.

I think it is unusual for a car with 85,000 to have a worn out converter, but it isn't out of the realm of possibility. When replacing the converter, they should check to make sure the engine control system is working properly and won't cause the next converter to fail too.

$1500 is a lot, but the Prius converter is different than a standard converter in shape and location, so part of the cost is due to the uniqueness of the part.

 

$1500, no wonder people are stealing them out from under parked cars. Yikes! Hopefully the wizards on this site can save you some money and figure out what those expensive "bugs" are.

 

i see you posted they did a fuel injector cleaning at 75k- that is probably too far in the past to be causative. well... it's a tough call, and you can't really prove it at this point. definitely not a failing 12v battery causing that code.

ask if they'll pick up the cost of the part if you'll pick up the rest of the cost (labor, shop fees, etc.) cats burning out in a prius are rare- they usually go because they're overworked or inundated with oil. the prius does neither.

ask for the old cat back from them and we'll give ya $20 for it. heck, we might even be able to pick it up since you're also in central nc.

 

For some codes, the light will come on and stay on until the code is cleared. For other codes, the light will come on, but if the problem is not detected again within a certain time period (usually defined by the number of drive cycles) then the light will go off until the problem is detected again.

For your P0420 code, the test is run once per drive cycle (problem detected) and the MIL light (check engine light) will stay on for 2 drive cycles and then go off if the problem is not detected again.

Your other problem codes could be actually problems, or they might be caused by someone who did not run the scan tool properly (e.g. didn't plug it into the DLC all the way) and got a communication error. You didn't post the actual code numbers, but all of the descriptions except for the first one are related to communication errors.

My dealership (that I bought my car from) works like this too. They only allow you to talk to the Service Advisor, not the actual tech that works on your car. And they take your car to the back of the facility, so you can't see if they are working on it or not. The Service Advisor I had was an idiot; he wasn't even a good liar, so I stopped taking my car to them.

 

well, its appearance depends on the usage patterns of the cat converter.

that throttle plate code is a problem. it could be that someone pushed the throttle butterfly open while the car was on and that registered as a code. it could be the throttle plate needs to be cleaned.

need to know the code number (letter and 4 numbers) for the immobilizer malfuction.

all those communication errors are common- nothing wrong there. also the solar sensor circuit. that means the car was indoors when they checked the codes.

the diagnosis is pretty simple. that code means that the catalytic converter is bad, there is no arguing or discussion about that code. P0420 means cat converter.

they don't usually offer to pay half- which is why you can probably the cost of the part out of them if you pay for labor. they probably feel there's something they did to contribute to that- a little guilt about how they performed that fuel injection service maybe? :/ at any rate, get what you can out of em, you've been a good customer to them and they want to keep you.

thanks!

 

Hi Galaxee,

Referring to the repair manual page that dogfriend posted above, note that the possible reasons for P0420 include an exhaust leak, a bad air/fuel ratio sensor upstream, a bad oxygen sensor downstream, or the catalytic converter. Also note that the catalytic converter is listed last.

Compare to my 2005 repair manual where the catalytic converter is first in the list of possible problems. I am wondering whether the editing on dogfriend's page was intended to discourage catalytic converter replacement prior to ruling out all other possible causes.

Hi toto princess,

It may be worth your while to inquire whether your tech followed the procedure to test the air/fuel ratio sensor and verified its proper operation. If that sensor had failed, its replacement would cost much less than the catalytic converter.

 

I think if the tech is thorough, they would look at the response of the downstream O2 sensor (voltage vs time) to see if it tracks with the upstream sensor or not. If it tracks the upstream sensor that would indicate that the cat is not working (that is what the ECU does when it runs the test). The ECU could get fooled by an exhaust leak or a bad O2 sensor, so the tech should rule those causes out.

Another test would be for the tech to put a probe in the tailpipe, essentially doing a smog test to see if the HC and NOx are elevated or not.

 

I am attaching all 7 pages for P0402 (don't tell Toyota). Basically the troubleshooting says to address any other codes first, rule out any exhaust leaks, then rule out a problem with the upstream sensor, then rule out a problem with the downstream sensor, if it isn't any of these, replace the cat.

 

cat clogged at 85k on a prius which uses motor half the time.... i'm going to have to call BS on this one... i really doubt that it's your cat... anyhow if it's your cat.. there are exhaust stores that will replace it for less than 300 ....

I'd go with O2 sensor before your cat... 98percent sure it's not your cat... unless you got a rat suck in there = )

 

What, nobody likes the failing 12V battery suggestion? We've seen many cases in which the low voltage of a failing 12V battery in a car of this age causes the computers to report random, intermittent, and false errors. It would be a mistake to buy a new cat before eliminating a much simpler and cheaper possibility.

Toto, it kinda sounds like you should get a second opinion from another Toyota dealer.

 

If the tech is following the troubleshooting procedure, they are supposed to verify the battery voltage as one of the initial steps.

Also, the P0402 test is only run when certain conditions are satisfied; one of those conditions is a minimum battery voltage. So, it doesn't seem likely to get the P0402 code from a failing battery.

The other codes could be related to a flakey battery.

 

the other codes are normal things that happen in day to day operations. ie, you press start button without sks present (or not detected.) you see these on a very regular basis but they do not kick a cel. they are not indicative of a problem including low 12v.

the reason DH is fairly sure that the problem is indeed the cat is:
1. she had a fuel injector cleaner run through the system recently.
2. dealership didn't even have to be asked to step up and offer part of the cost.

first things first, efi cleaners are usually linked to premature cat failures in a prius. since the engine does not normally run while the car just sits like other cars, the tech will commonly just stomp on the gas pedal to run the cleaner through. this overheats and melts the catalyst, leading to imminent failure.

secondly, the part is indeed about $1500. do you think the dealer would offer to eat half that cost UP FRONT if they weren't fairly certain that the problem was that expensive part, or that they probably had some causative role in the failure? remember this is not warranty- this comes right out of their profits. also, she could probably push them a little and get them to eat the entire part cost since they are in damage-control mode.

there are no other codes related to failures in the A/F sensor or O2 sensor present in this situation. DH has never, ever seen a P0420 without other related codes, that wasn't a cat. take that how you will.

if you want i can bring him back to the topic tonight when he gets home, but he's said what he has to say and it's not like this is something he hasn't gone through before.

 

So the moral of the story is don't let the shop talk you into a fuel injector cleaning unless you are actually having issues related to dirty fuel injectors. Which you probably won't have unless you are using bad gas (gas which doesn't have a good detergent package).

 

hence the warning in http://priuschat.com/forums/care-ma...70-what-services-you-need-what-you-don-t.html:
"since it doesn't idle, most techs will get in and stomp on the gas pedal until the EFI cleaner runs its course. this leads to a condition called "blinky check engine light" which means that you have overheated your catalyst and are in serious danger of melting the insides of your catalytic converter."

 

yeah, you can keep driving it. your emissions are higher, but it won't hurt the drivetrain any.

 

OK..This raises a question....with E10 fuel....I was under the impression that one of the benefits of E10 is that it cleans the injectors as a byproduct of being used. Is this right? If this is the case, why ever do an injector cleaning service?