2000 Honda Civic GX exhaust problems, need help.
 

I have a 2000 Honda Civic GX and I am getting several error messages.

cylinder 1 misfire
Multiple cylinder misfires
low o2 voltage
Catalytic system below threshold

I have replaced the spark plugs and spark plug wires. I have also cleaned the throttle body as well as replacing one of the o2 sensors. I am at the end of knowing how to find the problem. The next thing is replacing the Catalytic converter. Any help would be much appreciated. Thanks.

Re: 2000 Honda Civic GX exhaust problems, need help.
 

Do NOT replace the cat yet.
Misfires can kill even a brand new cat in a very short time. Sometimes mere minutes if it runs bad enough.

Fix all running problems first, then see if the cat code still returns after driving it.

Compression test?
Valve adjustment?