Catalytic Converter

Yes, four spark plugs is the correct number that you need.

As it sounds like money is tight, you might want to look at your engine air filter to make sure it needs to be replaced, before you buy a replacement. It's really easy to get to it.

Open the hood and find the black rectangular air filter housing that sits on top of the engine. Remove the four metal clips that hold the lid on, and remove the lid.

Now you will see the white air filter sitting in the housing. Remove the air filter and look at the bottom which is the side that catches the dirt.

Hold the filter up to sunlight. If you don't see much light coming through the paper element, then replace the filter. Compare to new if any doubts.

While you are looking around, look into the air ducting below the air filter housing to make sure there is no debris that has blown in. If there is, remove it. The presence of debris blocking air flow would certainly impair your gasoline engine performance.

Regarding which air filter to buy, I prefer the Toyota brand but aftermarket is acceptable as long as it fits tightly into the housing. Note the tab on the filter rubber gasket that fits into the corresponding cutout in the filter housing at the rear. Make sure the tab is placed into the cutout, which assures you that the filter is correctly installed.

Regarding the cabin air filter, this is hiding behind the glove compartment and you need to remove the lower glove compartment door to gain access. As this is not affecting your engine's performance, we can defer that for a later discussion. Or you can do a search for how to access and replace it. The cabin air filter is made of plastic and it is possible to wash with dishwash soap and reuse it if you want.

 

Hi all, I so I know this discussion is kind of old but I just got the CE light on my 2009 Prius (only owner) which is at 89K miles of mainly highway driving (my work commute is 30 miles each way), and that seems kind of early. Of course the Toyota dealership says it's code P0420 and no other codes are coming up, and that the O2 sensor is good, yada yada. They didn't check spark plugs or coil packs or cylinders because they said those have different codes and none of those codes came up, and because issues with those parts wouldn't cause the cat converter to go bad or the P0420 code to come up. I'm in TX so I'm out of luck with the warranty which ended at 80K miles. But does anyone agree that this is kind of early? Should I have those other parts checked, or is the odometer reading really more indicative that the cat is actually bad?? They did say I need a new air and cabin filters so I'll be replacing those, will that make any difference? I really appreciate any advice at all you guys can provide. Thank you!

 

I wonder what ever happened to MelissaAnne and her CC repair saga.

 

The consensus is that a faulty air/fuel ratio sensor can also result in that code. Considering the miles, it does seem possible it may be something other than the CC. Replacing the engine air filter is not likely to have any significant effect. The cabin filter will have no effect. But changing these filters, if needed, is beneficial for other reasons.

 

I have had 4 Prius' (Iam a small dealer specializing in 04-09 Prius) that I have had to replace the cat on. (P0420 code) I have always had a local muffler shop do it with the Magnaflow 99205HM. They charged me $299. I have never had one come back. If I ever have to do it again I will buy the part on eBay Magnaflow 99205HM Exhaust System Parts | eBay for $92 and have my local mechanic install it. Then I can sell the old cat to a scrapper for about $50

 

This looks like a good plan.

Not a large dataset but can you remember roughly the miles on each those 4 cars when you replaced the CC?

 

I did an 07 yesterday with 117k the other 3 were all 2005's with 150k+ miles and 3 of them were northern cars. Most of my cars are Florida cars.

 

Ok, thanks. That's good information.

 

Thanks SteveLee, is the air/fuel ratio sensor the same as the O2 sensor? Sorry if that's a dumb question. Because I asked them about the O2 sensor and they said it was fine. I asked the service advisor at my dealership so many questions about the whole issue that I think he was getting impatient. I don't think I can go back and have him replace the air/fuel ratio sensor, he'll probably say that's not the issue and still insist on replacing the CC. Thanks TampaPrius, I will look into that MagnaFlow. I think I have come across that one online.
What about the spark plugs and coil pack and cylinders, would that have any effect? The dealership didn't see a reason to check those either.

 

Nevermind the air/fuel ratio sensor question, I looked it up. I guess it would be worthwhile having both replaced, the one before and the one after the CC? Maybe the muffler shop can do that.

 

I think I want to use a direct fit:

Have you guys had good experiences purchasing from ebay sellers?

 

Duh, you did just say you would buy from ebay lol sorry - long day

 

you said he works 12 hours a day 7 days a week.that's 84 hours a week plus community. how many hours a week do you work?

 

There are NO aftermarket catalytic converters for sale IN California.

The online sellers including those in Ebay won't ship them to California addresses.

However, 49 state converters are legal in every other state save California.

I have a question though.

What if one takes the car to Nevada and registers it there ?

Can you put an aftermarket converter on in Nevada since they don't have the idiotic CARB rules there ?

Aftermarket 49 state converters for a Prius range from as low as $ 67 dollars to as high as $ 250 or more.

 

This is still true, there are no aftermarket cats for sale in Cali. But the post you just replied to was over 2.5 years old...

It is worth noting that the Magnaflow pictured above will require that the resonator be cut off the old cat and slipped over this new one. Straight-forward with a hack saw or sawzall. While there is nothing to stop anyone from driving to Vegas or Reno and paying cash at an auto parts store for one of these, there is also nothing to stop the smog-check people from a physical inspection of your exhaust system and giving you a fail for tampering.

Both Magnaflow and Walker versions of this type of replacement are sold by Amazon for the same price or cheaper than ebay.

 

On my 2006 Prius with 125,000 miles I got the dreaded P0420 Cat inefficiency code that has come on a few times over the past 3 months. I've been clearing, but finally had the dealership take a look to verify exactly what the problem is and sure enough the cat is going bad. Dealership quoted $2200 to replace the cat!! I started searching for alternatives and came across this thread and saw the recommendation of the Magnaflow 99205HM Universal Catalytic Converter sold for under $100 on amazon and promptly ordered. Thanks!!!!!

New cat will arrive on Saturday and be installed Thursday. I'll get some photos and post at that time. I have to say I'm really surprised that cats typically start failing so soon.

 

Also are there actually (2) cats on this car? Was just looking under it and saw what appears to be two and a large resonator. With the P0420 code I'm safe to assume only the first cat needs replaced?

 

There is one catalytic converter which is the part closest to the exhaust manifold. The oxygen sensor which is bolted to the exhaust pipe is downstream from the cc. Everything else would be a resonator, muffler, etc.

I assume you have the facilities available to cut the old cc off and weld the new cc on?

Please take a photo of the new part, prior to installing it, and another photo of the new cc welded to the existing exhaust system.

 

Patrick, thanks for the information. I watched the below video and confirmed on my car that it looks the same and it really appeared to me that there are two cats. What is the second cat looking piece then if it's not a cat? I can't imagine it's a resonator as the car already has a huge resonator and muffler to keep the sound in check.

 

I agree that the piece after the cc looks like a cc, but I don't think it is a cc because there is no oxygen sensor downstream to verify its condition. When you cut the old cc off, see if you can look into the pipe to determine what the inside of the second piece looks like.