You should get the exact codes that were pulled. maybe take it to
Autozone, they pull them for free. Then you can check. If a cat goes
bad, it's usually that the innards break up, which can cause rattling
and driveablility issues. It may simply be the O2 sensor. At any rate,
aftermarket cats are significantly cheaper than OEM - which it sounds
like your guy was quoting.

Dan D
'07 Ody EX
Central NJ USA

Find another garage as the mechanic is a parts replacer with no diagnostic
ability. The ECM compares the primary and secondary O2 senser to determine
if the cat is bad. If an O2 senser is bad It could also give a false cat
code. The O2 sensers can be checked with the
obd2 tester. Also those engines have a problem with the EGR ports in the
manifold carboning up. That causes an imbalance in the fuel trim and over a
period of time will burn out the cat. Check with your local Honda dealer for
the TSL on the EGR.

I had this happen to my 99 accord in 2003 or 2004.   My cat was replaced
under some emission recall or Honda emission TSB.  I don't remember what my
check engine code was.  You may want to hunt these links for your problem.
$1000 is what the dealer told me it would cost if I had to pay.

http://www.carcomplaints.com/Honda/Accord/1999/tsbs.shtml
http://www.hondaaccordforum.com/recalls-and-tsbs/browse.htm

I had this happen to my 99 accord in 2003 or 2004.   My cat was replaced
under some emission recall or Honda emission TSB.  I don't remember what my
check engine code was.  You may want to hunt these links for your problem.
$1000 is what the dealer told me it would cost if I had to pay.

http://www.carcomplaints.com/Honda/Accord/1999/tsbs.shtml
http://www.hondaaccordforum.com/recalls-and-tsbs/browse.htm

So the saga on this continues somewhat, I had the CAT replaced and
although I asked for an aftermarket there was none available. Another
factor is that about a month prior I had the timing belt changed and
also all the other belts and water pump, plus new front brakes and
rotors.. $1300.

So, we had the work done and they replaced the CAT and associated
hardware and the total bill was $1386!!

So, put on a few hundred miles and it was fine, and then .....yep...
check engine light. Only now my daughter has moved out of the area and
she is in New Jersey. So she gets an appointment at a dealer down in new
Jersey, D&C Honda and she drivers over there.. to get them to read the
code.. just before she drives in, the Check Engine light goes out.

The Service Manager tells me there is no sense in reading the code as it
is "probably a gas cap code" but also that if the light is off, the code
isn't stored. he says on a 99 it isn't stored.

Any idea on that from anyone?

Anyone buy the "Gas cap theory"... feels like a blow off to me.

Thanks,

Steve

PS She is in Leonia NJ, anyone have a suggestion for a good service
place down there?