I'm having a bunch of problems with my coupe.
It the 4cyl with a man. trans.
1st) I too have the dreaded O2 code even after changing the sensor and the CAT. And I cleared the code after install. Poof back on within 45 miles. NICE
2nd) I'm not sure if it would be the surging problem people mention but while driving, electrical power starts to go out (no A/C, and stock radio)The tach dips and drops then the engine shutters.... and as quick as it happened- gone. Sometimes the SRS light comes on too. I have video of this happening.
3rd) from time to time there is a electrical whining sound like it's coming from under the dash. Reminiscent of the old amp we use to put in our cars in the 80's (don't judge) thinking that might be the alt. starting to go out.
4th) the worst one. Dead Car. Sometimes when I shut the car off the whole thing goes dead, like the battery was taken out. Door locks, lights, engine, Nothing works. And after a few hours.. boom, it's all on again. But now the clock is at 12:00 and the radio is cleared.
The only code I get is the P0420.
HELP PLEASE....

 

I would start with the simple stuff first. Disconnect the battery, then clean all ends of both battery cables with a wire brush or sand paper. Carefully inspect the battery cables for signs of corrosion. Inspect the connection to the alternator while the battery is disconnected. Once you do this, have your battery/alternator tested at a parts store. Use a 10mm socket to tighten the clamps onto the battery post, because a 10mm boxed end doesn't secure the clamp on the post (guess how I know?).

Since the clock resets, I would not suspect a faulty ignition switch. There was a recall on accords of that era, so call your dealership to find out if your car had that done. You can try shaking the key to see if the engine stalls while the car is running.

The P0420 sounds like a different issue. When you replaced the cat, did you buy a Honda one? You may want to check for exhaust leaks that can fool your secondary O2 sensor.

 

What engine?
There were ULEV engines in 1998 that require a different primary O2 sensor. Make sure you know whether you have a ULEV and that you got the correct sensor.
F23A1 = VTEC (non-ULEV)
F23A4 = ULEV-VTEC
F23A5 = non-VTEC (Accord-DX??)

 

Sorry about that, F23A1 = VTEC (non-ULEV) engine.
And I have replaced the ignition switch, but it wasn't covered under the recall. I did did replace the CAT. but with an after market unit. I didn't think there would be moch of a difference. And there are no leaks in the exhaust system.
The nest thing I can do is take off the alt. at run it to the parts store and have it tested, but all the alt. connections are good and clean.

 

You are losing connection somewhere. I've never had a vehicle so sensitive as my 97 accord when it comes to the battery connections. I was having issues and cleaned everything up nice and ended up having to clean more and get nice Shiney lead going on before my issue was corrected.


Cliffs: hyper clean the connections at the batt. If problem remains start tracing it for a broke wire/loose connection towards the fuse box.