Ge-money

So i just got this 98 civic and previous owner told me it didnt pass smog and he thought it was a bad cat.. He didnt give me the fail results so i didnt really have a starting point to see what is wrong.. car runs great no CEL no problems..

so i decided just to try the old denaturated alcohol trick and see if i could get by with a pass. I was near empty with maybe a gallon or 2 of gas in the tank and threw in a quart of alcohol in the tank and really got on the car for a few minutes driving to the shop to heat up the cat.

My question is for those who have tried this method.. does alcohol lower CO specifically? Because im thinking i didnt put enough based on the fact I bearly failed 15mph test only..

Any opinnions appreciated.. I have a free test and need to get this thing passed.
If i just fix the necessary what causes high CO?

Thanks

Ge-money

anybody?

Ge-money

bump

B20DelSol

Well...looking at it, you Hydrocarbons (HC) are relatively high but within Gov. spec. I to it could be the cat going bad but there are other places you can try before spends $200+ for a cat. I see you have no MIL light set so that is good. It also means that for the most part you O2 sensors are functioning.

Now, everyone will probably ding me for saying this, but I recommend it to all who have just purchased a used car.

Start with a basic tune-up:
Spark plugs (NGK)
Wires (OEM, NGK, or Beck/Arnley)
Distributor Cap and Rotor
PCV valve
Air Filter
Fuel Filter
Oil Change w/ New Oil Filter

You could also do a seafoam treatment through your brake booster line before you change the plugs.

I would start here since this is normal maintenance stuff that will have to be done at some point.

The high HC and CO (primarily HC) means you have unburned fuel in the exhaust. Taking care of this normal stuff rules out many factors before replacing the cat or sensors.

Hope this helps a bit!

And if this does not work, check ign. timing, cam timing, O2 Sensors using a scope, or replace the cat or all of this