The sensor that you refer to is the rear O2. Did you mess with it? If the shield was solid and you bang on the cat and hear loose pieces of the element rattling inside, you need a new cat.

 

Indeed, it is code P0420. And as suggested, it must be loose pieces of elements, and I need a new cat. I didn't mess with the oxygen sensor yet (to answer falkore24).

By the way, I downloaded the manual "Honda ESM-Accord 1998 v1.4.0",from the link providedby this forum (its FREE). My engine is F23A1 type (4cyl, 2.3L VTEC). The ones the manual describes in "Exhaust Pipe and Muffler Replacement" deals with D16B6, F18B2, F18B3, and F20B6. Which one should I go with (I mean not only for this section but in general too)?

 

00AccordLX5PD stating that the code P0420 is a Cat. Convertor code. My check Engine Light came on Last month and I replace the Oxygen Sensor conencted to the Cat and it never came back. Its been over a month a half and driven 2000 miles. No problems so far with the light coming back but will keep you posted. Just want to share the info with you.

 

It can take longer than a month. P0420 IS a cat code. Not an o2 sensor code. I have heard of o2 sensor being replaced when code P0420 was readand taking as long as 3 months before the CEL came back on. But it still came back on....with the same code.
Besides...I would try the "defouler" trick ($5) before spending over $100 on a new o2 sensor.

 

I was going to replace the cat myself but I'm in two minds right now. I've got all the part with me so I feel bad letting this go. So please help me out.
The problem is the nuts and bolts holding the old cat is rusted and stuck real bad. MY OPTIONS:-
1)I need to cut six nuts and six bolts and somehow hammer out six bits of screws to get rid of the old cat. I don't know if that's my cup of tea. Especially since some of the nut/bolts are in awkward position.
2) Should I (also can I) just take the parts to a professional and pay for labor?
3) How about having the old cat removed professionally and do the installation myself (Would it be feasible to drive the car back home to do the job in such a state. I mean wouldn't the exhast dangle down midway)?

 

A mechanic did the work for me for an hour worth of labor (I supplied the cat and gaskets). The engine light is still on, but I'm told it would take another couple of hundred miles or so of driving until it resets itself.

I gather that for older cars, any exhaust line work would likely involve some cutting and welding.

Thanks everyone for your feedbacks.

 

pull the ground lead from the battery and leave it off for a half hour (wrap with a plastic bag and a rubber band). This should reset the ECU.

 

That worked!! The engine light is reset after I plugged out the battery. Thanks falkore23!

 

Hey ..... 23?!? Glad it was an easy fix!