Had the car for about eleven years and it finally failed smog.

Information about the car:
Dx model
Swapped it out for a Non-vtec SOHC ZC about ten years ago
Engine wise everything is stock


Before I take the car to get smog, I do the typical things:

- Change oil (Mobil 10w 30)
- Change oil filter (Honda Oil filter)
- Replace spark plugs (NGK OEM replacements)
- Replace air filter (STP 5333 OEM replacement)
- Fill it up with 87 Octane from Arco
- Checked the timing
- On the day of the smog I run the car on the freeway for about an hour.

Things I had recently done was:
- Replaced valve cover gasket (OEM Honda)
- Replaced spark plug tubes (Felpro)
- Replaced oil pressure sensor (Napa brand)
- Installed a new HKS exhaust a week ago

- Had a new CAT installed about two years ago

Here's the results:

 

High NO and HC both have common failure modes with lean fuel mixture and faulty cat converter.
Your HC isn't crazy high so I'm leaning towards the lean fuel.

My guess is that the O2 sensor is getting old and lazy.

 

I always run octane booster, supreme gas and do an oil change before smog.

 

Agree with 4DREF...O2 sensor could or is on the way out.

 

which cat did you use?

perhaps these aftermarket ones really arent that effective?

 

retard timing as much as possible!

 

Winner! I bought a brand new cat.

Catco brand. They had two different kinds; one was small and the other was large. I opted for the large one and they surprisingly cost the same. I'm assuming one was for a 1.5 SOHC and the other was for a 1.6 SOHC. After having it installed I took it for a drive on the freeway for an hour and had it smog. Very big difference in results.

Few things I'm concerned about. My HC levels are still somewhat high. What are some things I should be looking into diagnosing and getting replaced. I'm assuming this next issue is related to my HC levels as well, but I noticed after I installed my HKS exhaust that it seems I am getting oil mixed with water being spitted out. I've touched the substance and it is indeed watery and either oil or exhaust fumes. On that note, when I rev the motor up, it is also blowing out white smoke.

 

You shouldn't be getting oil in your exhaust. My guess would be worn/bad piston rings.