I don't have an Air/Fuel ratio gauge. The color of the exhaust just gets a little black not too much and the smell is not bad (normal scent)it's just smells the same like on my 94 accord

 

Are you having any engine problems? Are you experiencing poor gas mileage or engine performance? If the answers to these questions are NO, then I don't think you have much to worry about.

 

No but I get the stupid check engine light for code P0420 then I erase it and then comes back On after 70 miles or so

this is the print out I got from Auto Zone.

Definition: Catalyst Efficiency low-bank 1

Explanation: The oxygen sensor monitor the catalytic converters ability to store oxygen

Probable causes:
1. Catalytic converter defective (failure possibly due to #2,3,or4
2. Engine misfire or running condition
3. Large vacuum leaks
4. Engine oil leakage into exhaust-valve guide seals, piston rings

I have a magnaflow cat OBDII compliant and carb epa approved.. I don't know if the cat could be a problem
NO oil leaks. It's not an engine misfire or running condition
Last time I checked for vacuum leaks it was all good. When I had those stalling problems my Honda dealer looked for VACUUM leaks and no leaks.
Could it be the cat????

 

The code "P040" is missing one digit. Do you mean P0401?



If you are not sure, you might want to retrieve the code using the jumper wire method:

http://www.honda-tech.com/zerothread/1901557

If your code is P0420, then your catalytic converter is probably dead. Alternatively, you have an exhaust leak. If your cat is dead, this might have happened when your car was having stalling problems, which was likely due to misfiring.

 

My bad RonJ....yeah it was P0420.
So more likely the cat is dead. last time I checked the honeycomb it was still looking real good...No sign of blackish colors

 

In general, code P0420 is thrown for one of three possible reasons (see picture 1):

1) Bad cat
2) Exhaust leak
3) Bad secondary O2 sensor

Picture 2 describes how to inspect the cat.

If you are unable to find any cat damage, then try to find an exhaust leak. I don't know how you test for such a leak -- maybe take the car to a muffler shop and ask them to inspect the exhaust system for you.

If the secondary O2 sensor is bad, then you might expect to retrieve a fault code for it. However, if pursuit of other avenues doesn't yield a solution, then you may want to try replacing the secondary O2 sensor.

 

Yeah I will take a look at the cat..It still under warranty Hope they want to help me out. I doubt it they will replace it for free.

 

This problem will likely prove to be less complicated than your stalling problem. I hope the fix is inexpensive.

 

the cat has a 5 yr or 50,000 mile warranty what ever comes 1st. But they are going to be bitching about that my car had a mechanical problem and that cause the cat to get ruin again. A good buddy of mine works at my local Honda dealer I will tell him to write me up a paper stating that cat was bad and everything else is working properly.I been there before so they have a record of my car.Hope they take the bait at that muffler shop..
O yeahI purchase that cat about 6 months ago

 

Yes my cat was burned off...DEAD :[ but hey I got a new one they replace it for free since it was still under warranty..I kept my old cat and I'm selling it on e-bay for scrap.. Extra cash yes..
That will get me my 99-00 civic fog lights and some JDM Stanley OEM clear side markers..awesome

the inlet side of the cat****


and the outleat of the cat..