Replaced 3 catalytic converters in a 20 month time frame

Yes, I just had the third cat replaced in a 20 month time frame. I own a 2000 Honda Civic which I get serviced for regular and scheduled maintenance. It currently has 81,000 miles The dealer replaced the cat in Mar '08 @ 66,000 miles and again in July '08 @ 70,000 miles. It’s now Nov '09 and they’ve replaced another cat (luckliy I have not paid out a dime). However, it’s clear that dealer is not getting to the route of the problem as my vehicle is ruining catalytic converters in an untimely fashion. I know that the ECU is covered under the EPA 8/80 emmissions warranty and I’m afraid that the dealer has been slapping a band-aid on my problem by failing to address/point out the possibility of the ECU being at the root of the problem. Can a non-Honda service shop determine if my ECU is good, bad or otherwise?

My guess is the CEL (Check Engine Light) is coming on. After it comes on take it to one of the auto part stores that will read the error code for free and come back and post the results here.

In the mean time get written documentation of everything that has been done and check your states lemon law

No, the check engine light is not on. But every time it has come on, it’s been: P0420.

The last cat was just put on a couple days ago, but I’m guessing a new cat is not the solution to the real problem, as each time they put on a new cat, it goes bad. So I’m trying to figure out what it is that the dealer is not figuring out. In other words, what is the real route cause of my car needing a new cat every few months.

I’ll check out the lemon law info. Thanks!

The dealer is required to have the Honda scan tool which has extensive troubleshooting charts for DTC trouble codes. Apparently, they aren’t following those troubleshooting charts, or, don’t comprehend them.
Has the dealer’s mechanics listed any troubleshooting performed? Perhaps, you should call the regional Honda rep and tell them of the problem. Honda America can send one of their tech experts, if they wish. That may be needed.

The dealer claims that they have gathered information from their diagnostic tools and even sent my case with the diagnosis data to the engineering department in California. I was told that engineering instructed my dealer to replace the cat. No matter how much I expressed my concern that this is not getting to the root of the problem, the dealer said that replacing the cat was the best approach. All of this makes me highly suspcious that they are intentionally avoiding something bigger that could fall on their dollar.

This happened to me when I had bad (cheap replacement) plug wires.

9 years old = no lemon law.

You are on your own with a car like that except for repair shop/parts warranty.

You are correct Ameila, The CAT is NOT the root problem. Cats burn up because of overheating from trying to clean up the exhaust that is delivered to it. It is getting entirely too much raw fuel (hc) run through it and your dealer is not doing what you have asked him repeatedly. This engine has ANOTHER problem. Do as the previous posters have asked (get the codes) & post them here.
Secondly I would go to a DIFFERENT DEALER. TWO CATS IN 4,000 miles!! Gawd this dealer is stupid!!
I highly doubt that the dealer sent your service records and diagnosis info to the regional enineer. If they had, the engineer would have spotted the first 2 cats in 4,000 miles and told them to fix the underlying problem…
It’s dealerships like this that give all dealers and mechanics a bad name…

it doesn’t necessarily have to be a bad ECU causeing this. It could be something as simple as a plug wire like “melott” said, or fuel mixture adjustment.