I'm going to replace the O2 sensor, but what else can cause the car to run rich ?? Or better yet, what can I do to lower the CO's???
It is an LG4, mods in the sig. This is the first time I'm having problems with emissions.......

Hydros are fine so is NOx..............

 

From the pre-printed back side of my emissions printout:
"Common causes of excessive emissions":
"High CO carbon monoxide":
"Air cleaner, choke or carb malfunction"
"Dirty air cleaner, choke or carburetor"
"Carburetor float level misadjusted"
"Incorrect carburetor settings/adjustments"
"Inoperative/missing catalytic converter"
"Defective evaporative system"
"Faulty computer controls"

I left out the stuff that addresses fuel injection problems.

Certainly do the cheap stuff first - air filter, evap filter, PCV valve, O2 sensor. Make sure the choke is coming off all the way. Have a fresh oil change just before having it tested. Q-jets are known to leak out of the bottom passage plugs (clean, cover with epoxy if you think they may be leaking). Set the idle air bleed to the proper dwell. If those don't do it, it's going to get more expensive.

I went through this three straight times with my '84 full-size van. I went through all of the above (except O2 sensor and IAB dwell), even put a new Edelbrock q-jet on it (it's a non-CC system). I failed the first test three times in a row (over 6 years, tested every other year), just barely getting by in the retest the first 2 times. This last time, I did what everybody told me wouldn't help - replaced the cat.

Emissions dropped to the basement. Turns out the cat was an empty can all these years (was burned out by the original engine pumping oil into it).

 

Cat is relatively new, about 10,000 miles, that and NOx was very low. So the Cat is good, will check all the other items on the list, thanks.....

 

i think there is another non emissions county there in NY
--Dan

 

Well I passed with flying colors! My CO's dropped by 10 points Here is what did,

-changed O2 sensor, was about 5 years old...

-changed hanger and rods back to stock (the secondaries open on hill test)

-little carb cleaner

-dry gas and drove it to empty.

Here are the results:

HC CO NOx

Test Limits: 1.2 15.00 2.5

Results: .53 10.95 .43

 

is that 15.00 percent on the CO?

in california im only allowed to have .78 percent CO.
my car keeps putting out at least 9 percent which is WAY off. i havent even come close to passing!!!!
HELP

 

What do u have?? What mods, etc, please tell us so we can help you. In general, from my research if CO's are high the car is running rich. Use the info in this post to start.