Check Engine light came on back in 2005. At that time I was told to have Autozone check my codes. They got the po420 code. I was told it could be various issues related to catalytic converter. I called honda just to see what it would cost and it was way too much but the guy in service told me to try a muffler shop and pay much less. The car was/is running fine and someone told me they had the same code and light had been on their car for over a year. I know this is not a good idea but I have been driving mine with the light on for 4 years now. No problems at all and same gas mileage (30mpg) all this time.

I am getting the car ready to sell and want to get rid of Check Engine light but also want to fix the problem. I went to a muffler place today and the guy told me that 99% of the time the car does not need a catalytic converter or even a sensor especially if i have been driving it 4 years with no problems. He says some times it is just a bad gas cap, plugs or connection. The light used to come on every few weeks in the beginning. I would reset it and wait a week or so for it to come back but eventually it was coming on more often. He did a free test today and got the same code but said some things were not showing up on his tester and that was odd. For $70.00 he say they can do a diagnostic test that he guarantees will find the problem. But it does not go towards fixing it once they find out what is wrong. Does this sound bogus or is it that difficult to diagnose the problem. He reset the Check Engine light after he tested it and I was going to buy a gas cap a couple of miles down the road in case there was a chance that this was the problem, but the light came on again after 10 minutes. My gas cap is the original. I would appreciate any tips. Yes I know I was stupid letting the light stay on all his time, but at least it will be fixed for new owner

OH I almost forgot>My regular garage (former honda mechanic) did a 120,000 mile service on my car @ 120,000 miles on 12/06. I had him test the Check Engine light also and he told me that I needed a catalytic converter for $716.00. He only replaces with Honda parts so I guess that is how he came up with $716.00. I think he told me the car would eventually stop running. That was almost 3 years ago, so I don't know who to believe.

 

Out of the many posts, this one attract my attention. I believe it is possible for anyone to participate.
Excellent ! I like it very much.

 

Well you are way beyond any extended/goodwill warranty, but this is a common problem in those years. You might have had a chance for a freebie at the dealer 4 years ago.
I'd say to bite the bullet and replace the cat converter.
FWIW; the local metal recycler will pay some $$ for the old converter.

 

So the $ 70.00 diagnostic test is probably bogus? And if it the cat converter went bad over 30,000 miles ago the car will still run fine today?

 

it needs a cat conv ,, if you buy a Honda one part is about 700 dollars , a non-Honda conv is a lot cheaper but issue will come back within 2- 3 months ......been there , done that
I had to replace 3 non honda cats and code came back within 2-3 months,, had to warranty parts + labor,, finally installed a Honda cat, 2 1/2 years ago ,, still no code ..

 

Got a new converter. That seems to of been the problem. Sensors checked out fine. Price went up around $50.00 from last time I got estimates. The cat came with 2 year warranty. Thanks for all the help.