Robert Stern

Hi All,

I live in NV and just went to get a smog check on a 93 Del Sol Si with d61z6 I just purchased used. Since I got it used, i haven't done anything but charge the a/c , change the oil, and seal with a gasket the header to exhaust system. It was missing a bolt and didn't have a gasket, so wasn't sealed. But it is now.

Any help is greatly appreciated.

Here is the info I was given at the smog shop:

Failed:
IDLE SPEED CO = 1.72% Max 1.20% for pass
HIGH SPEED CO = 1.31% Max 1.20% for pass
IDLE SPEED HC = 3765ppm Max 220ppm for pass
HIGH SPEED HC = 412 Max 220ppm for pass

my car has a generic k/n style air intake
generic non-stock "performance" header system
generic non-stock "performance" exhaust muffler

EJ8_Man

High Hydrocarbon (HC) emissions are almost always a sign of poor fuel ignition and/or a defective catalytic converter (CAT) may be responsible for high HC, CO, and NOx emissions. Check your ignition components and ignition timing. If that all checks out, its your CAT

Not to be an ***, but here is where I stole my info from:
http://lmgtfy.com/?q=Cause+of+High+HC+emissons

First link

Robert Stern

Put the ECU in service mode, and it was pinging back EACV and O2 sensor.

Checked them out, completely Black with carbon. Cleaned them up and re-installed. Also cleaned out the throttle body as well.

Spark plugs were some generic crap. Replaced them with the stock NGK's.

Reset the ignition timing, was way off.

Reset the ECU. Seems to be running much better now, idle is stable and exhaust fumes aren't are rich with gas type smell anymore.

I was told that if I fail smog 3 times in NV, then I have to go to DMV to pass smog directly and they won't accept a JDM motor swap, and will require me to get a USM Motor.

So, I will have to find someone that can run the smog tests with out reporting to dmv to see if I will pass before I take the official test.

Robert Stern

HI all,

So since the last post I have seafoamed, replaced the fuel filter. Drove about 150 miles on it...

Went to a place that would run the test from me and now:

Idle = 2800 HC 1.48 CO

Hi Speed = 450 HC 1.13 CO

The guy at the shop, honda exclusive shop seems to think it's not the CAT?

Any idea on what else I could check?

RlMcCoy71

I would start with the o2 sensor. They're not too expensive and easy to change. Cleaning rarely solves the poblem, and seeing that you had an O2 code it goes with reason.

Robert Stern

The O2 sensor was pretty black with carbon. And was giving the code. Although after I cleaned it and let it dry, reinstalled the code disappeared.

Robert Stern

Decided to do a compression test, and my 2nd cylinder is jacked.

1st 2nd 3rd 4th
Dry 185 100 200 200

Wet 245 160 250 245


Pretty sure this is the reason I have super high HC at idle.

ej7attack

My d motor is doing the same thing it seems like. Except mine now consumes 2 quarts a week. Pretty sure its piston ring blow by, causing misfire codes so it runs rich.
Mine i would say is a bit of an extreme case lol!

Robert Stern

Any idea's on what I should do next?

A Leak Down Test?