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.

 

sounds like people have been giving you missinformation...

you're car won't stop running if you ignore a p0420. i believe the gas cap is a different code, and it won't effect the cars ability to work properly. if you're selling the car, i wouldn't spend the money to put a honda cat on. find a place you like to deal with who will put an inexspensive converter on and your light should be gone and you can sell the car. i wouldn't pay anymore to have it diagnosed untill a new cat is on and the light is gone..

you could even do the work yourself... some good penetrating oil, a good socket set, some extensions and a wrench or two... the only thing that keeps this from being a super easy job is the amount of rust on the bolts.

 

I would not be able to do the work myself so I would have to go for replacement. If it the cat converter was causing the Check Engine light to come one over 30,000 miles ago the car will still run fine today?

 

yeah, all it's saying is that the converter isn't cleaning the exhaust like it should. as you may know, the cat has no part in the function of the engine, it's a result of the Clean Air Act in part.

you're primary o2 sensor which can and does effect the functioning of the engine is up-stream from the converter so the engine continues to work fine since the "bad" converter doesn't affect the reading.