just get a new cat meng. they're not that expensive.

if it's throwing an O2 and catalyst code, i'd almost gurantee the o2 sensor that's tossing the code is the secondary.

I though I would bring you up to date: I brought the car after the CEL came on again to my Honda Dealer who found the code for the catalytic converter P0420. I paid $1100 for the replacement. That same day I took your advise and called American Honda, just for the heck of it, not expecting anything. They are going to reimburse me $950 of my money as a good will gesture in hopes that I will buy a Honda in the future. I must say that the people I had contact with were cordial and very professional at the dealer and at American Honda. I feel that the "little guy" finally won one. Thanks again for the help.

Okay... I have a 99 Accord EX with the same code - comes on around once a month or so.

Are you guys saying that Honda will cover this for free?

I would say it depends on what your mileage is. My mileage was 83,900 about 3,900 over the limit. Also I purchased the car at that same dealer as a certified used Honda and I serviced it there often. It is certainly worth a shot though in any case. Remember be very courteous when you call because they really do not have to help you at all.

An O2 sensor from the dealer will probably be $150 + or - and I was quoted like $776 for a cat. for my 95, which is complete crap. You can get an aftermarket Magnaflow cat. for $72 from SummitRacing.com if you had to.

Very rare that cats. go bad, though it does happen. And to everyone else's point, you can get something like a Denso (good stuff) O2 sensor much cheaper and install it yourself to see if that fixes the problem before you get into a new cat. I put a new Denso O2 on my car not too long ago. It's easy, it just may need a little persuasion to break loose. ;)

And be sure you don't run lots of fuel and carb. cleaners and all that crap on an ongoing basis through your car because those are bad for your O2 sensor and cat. in the long run.

Fixed my Cat. Problem: http://cgi.ebay.com/ebaymotors/HONDA...35416545QQrdZ1

P0420 is catalyst effency below threshold just means the cat doesn't meet ULEV standards but will pass a normal test I've seen many people just reset the computer drive it down to the smog shop warmed up pass the test then drive home and have the light come back on the next day as it needs 2 complete ideal drive cycles to come back on . glad honda did a good will reimburstment . the next time you get that code just use the fouler trick -works like a charm :D

it looks like a $1 capacitor they are selling for $16.50 and you still have to trick the heater part or leave the O2 connected

Yep. I did that for last year's inspection but this year I just bought a Honda factory cat ($202 on ebay) because I'm sick of getting the 'rotten egg' smell every time I go up a hill and my MPG hasn't been better than 27 on the highway since i started getting PO420...I used to get 29-30 all day long.

i just had my catalytic converter changed and it cost 211 installed tax included