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Failed Cat Converter

I have a 2005 Accord, 5 speed, with 82,953 miles. My check engine light kept going off and on (on for 3 days, off for 1, then on again for two etc) so I took it to the dealer. They said I need a new Cat converter and quoted a price of $1070.
Is this a reasonable price - I’ve read on this site about after market prices for Cat converters being less but what does that mean ? Would I have to order the Cat converter from somewhere and then BRING it to a repair shop for install ? And if that’s what I would need to do - what sort of savings would that give me ?

The catalytic converter is warranted by manufacterer 8 years/80,000 miles. I know you’re over the mileage by 2,953, but ask the dealer if they can do a good-will adjustment on the replacement.

Explain to them that you bought your Honda because you believed it was a quality vehicle. And you would have never bought the car had you known that catalytic converter would only last just out of the warranty period.

Can’t hurt to ask.


And first make sure it’s the cat. Go to autozone, etc and have the codes checked. Many things set off the ‘cat efficiency’ code, like a bad O2 sensor.

Even if the cat is bad, something else may have damaged it. If you don’t have that fixed, the new one will also be ruined.

Did the dealer perform a proper diagnosis? Many p0420 and p0420 codes are caused by failing oxygen sensors.

On top of that, many cats buy the farm because of misfires, leaking injectors, blown headgaskets, etc. I’d want to be 100% sure NONE of the above applies to you.

We wouldn’t want to have you buy the cat, only to have the very same code come back on a few weeks later.

As far as the price, that sounds plausible. A factory cat is quite pricey. Aftermarket cats are cheaper, but they may not fit as well, and they may not last as long. They also may not have enough of the precious metals, which could cause that same P0420 code.

If you go to an independent shop, have them source the part for you, but make sure it meets all the requirements for your state. In California, there are very few CARB approved aftermarket cats.

Of course you would save substantial money at an independent shop.


If you do need a cat I’d get mine from Rockauto, factory - fit ones are about $200 each (you’d need two if you have the V6). Which engine do you have?

What you don’t want are ‘generic’ cats.

Thanks for all the phenomenal advice ! I actually didn’t ever see the “diagnostic code” but clearly I should - so how would I get that done at AutoZone ? The AZ’s I’ve been to don’t have a mechanic/repair shop.

You just ask the guy at the counter, he takes a codereader out to the car, hooks it up, and tells you what the codes are, like “P0420”, that kind of thing.

It is sort of unusual for an original-to-the-car cat to fail at 80K. As mentioned above, it is worth doing a little more investigation before opting for the cat replacement I think. All good suggestions above. For a 2005 Honda out of warranty – if after verifying the dealer won’t help defray the cost – if it were my car I’d have it done by an independent shop which specializes in Hondas or at least Japanese cars.

If you live in Calif, you may have a Calif-state-emissions warranty that lasts 100K btw. Calif requires all new car emissions systems be warranted for 100K I think. And other states may do this too. It’s worth the time to ask about this.

And before installing a new one, I’d ask the shop to bring all the routine maintenace items suggested in the owner’s manual for the car up to date. A poorly running engine can reduce the longetivity of a new cat.

If you still have the paperwork from the dealer, the code should be listed on it.

Again fantastic advice THANKS ! Sadly, i don’t live in CA - so no extension of warranty. This is my 3rd Honda and this prob did surprise me since I took a prelude to 112k miles w/o any such prob. When I asked if this happens a lot, the dealer said it was not a common prob but does happen ie it’s not unheard of.
The dealer is offering 15% discount that’s what brings the cost down to $1070.50. Unfortunately the paperwork only says “99 needs new bank 1 cat converter” under the word “1 cat” is the number 597. Soo am missing the diagnostic code ? Or is the 597 the code ?
So I guess I need to go to an Autozone and get a diagnostic code to confirm the problem and then price the repair at a reputable Honda repair shop (non-dealer).

There is no code 597. Might be the price of the part. I checked Majestic Honda and see two cats, one for $581 and another for $334 (OEM parts). Probably depends on whether your Accord was made in the US or Japan.

I would not consider doing this job anywhere but the dealer unless the shop gives you a very good warranty.

I would do a lot of checking to see if I really needed a new CAT., before I would pay that much .

+1 for Elly Ellis. A lot of catalytic converters go to the scrap heap that had nothing wrong with them.