Hello everyone, i have been having this issue for a while, and it needs to be fixed promptly.

i have a 1992 EG hatch with a d16z6 completely bone stock, and it has failed smog 3 times the following is what i have done.

all parts less than 50 miles on them

oil change,
new fuel filter
new NGK spark plugs
new distributor cap & rotor
seafoam the engine through brake booster vacuum line.
new air filter
checked timing, its at 18BTDC

i ran premium on it, heard mixed stories about it, and i wanted to try isopropyl alcohol in the tank, just a little, all inputs welcome.

i am assuming its the catalytic converter, but i do have one more thing to change, the o2 sensor, i'm picking one up here shortly.

i live on base so i really don't drive the car anywhere, anyway, here are my smog results.

BTW i live in san diego.

15mph run

HC:max is 108 i measured 206
CO:max is 0.57 i measured 0.63
NO:max is 835 i measured a whopping 2045.

25mph run

HC:max is 73 i measured 80
CO:max is 0.48 i measured 0.20
NO:max is 542 i measured 285

please help, im sure the cat would help but i wanna know what else i can do.

 

your cat is the problem... all your scores are high = bad cat... bad 02 will usually throw a code when bad..

1.RUN 87 it burns a lot faster than 91 and takes less energy to burn *this is better for combustion effciency*
2.run 1 bottle of RED ISO-HEET an hour/ before driving to smog shop and heat up your nre cat make sure its hot/warm while testing.
3. set your ignition timing to 16degrees (the way you have it is ignition retarded less burn fuel) you can go as low was 14,15 best. (try 16 just because thats stock for z6)
4. when you get a cat make sure its a OEM cat (aftermarket ones tend to suck, they lack the materials needed to do the job right)

 

sucks to live in cali, I just had my cel reset for my bad cat and I passed inspection real easy

 

the high NO numbers would also indicate incomplete burn and high exhaust temps - fuel is burning in your exhaust and might be what killed your cat. As previously stated go to 87 and run a few more degrees of base timing.

Regards,
Ray

 

Post the actual emissions sheet.