nicknack25

So my friends 2000 Accord just failed smog. His numbers:

MAX MEAS
15 MPH HC- 56 119 (FAILED)
CO-.51 .56 (FAILED)
NO- 443 966 (FAILED)

25 MPH HC- 40 122 (FAILED)
CO- .49 .59 (FAILED)
NO- 730 565 (PASS)

Those numbers are pretty high. I'm leaning toward a new cat.

Just got a new o2 in recently, and changed oil, plugs, wires, cap and rotor, air filter, timing belt, water pump, coolant, and thermostat about 3000 miles or less ago.

Everything is stock. Don't remember what his mileage was but it was pretty high. Close to 200K.

Do you guys think i can maybe sea foam, adjust valve lash, and use Heet that we might be able to pass the car? Or should we just get a new cat?

Thanks for looking

mrj_accord

its check and worth a shot!
they will refund ur $$ if u fail after using it.

MAD_MIKE

Don't jump to conclusions just yet. What was the CO2 and O2 readings, use an IR gun and see what temperature the catalyst is at when at normal operating temp. It should be ~750°F for maximum purification.

At 200K if the EGR ports have never been cleaned they are probably gummed up a good deal, this would cause a lean misfire which will indicate both a lean and rich issue as well as an increase in NOx emissions. Purchase a new EGR valve gasket, and a upper intake plenum gasket. To clean the EGR ports on a F23...
IMO this would be the easiest/cheapest thing to check and verify.
From RockAuto the gaskets would cost ~$5+shipping.

Have there been any misfire(P030*), catalyst below threshold(P0420), or insufficient EGR flow(P0401) codes? Does the car have a slight stumble or hesitation while at cruise RPM? Just because a code is not set or saved does not mean there is not a problem with a system

Make sure the CEL light does indeed work. Here in Calif the smog techs should be checking for the CEL and or any active codes, but sometimes they are lazy.

If any tuneup work was done right before going for the smog test, this will skew the test numbers as a new ignition system will burn hotter and burn off some of the carbon deposits in the combustion chamber. This will elevate emissions output as the deposits are removed.

What brand of O2 was used? Only use Denso or NTK.

holmesnmanny

You may have an exhaust leak. You should check that. You can use seafoam to find an exhaust leak. You will see white smoking coming out of the exhaust anywhere from the exhaust manifold to the oxygen sensor. Look carefully there as you seafoam.

etomas6

Did a cat work for you? Im kinda in the same boat... Except with my del sol. Its gotta b16a3. Except here in washington we test at cruise (2500 rpm) then at idle. the curise was fine, i was at 348 HC (PPM) max allowable limit was 400. at idle though it shot up to 1042!!? any ideas? P.S the resonator has about a finger size hole in it.. lol

nicknack25

Well after we got the cat in, it was still running rich, and the check engine light was still there. The cat did help a lot, but still failed. Changed both o2 sensors, and check engine light went away and we passed.

nicknack25

It was our primary o2 sensor that failed.