Car Inspection Question - High CO

[Carbonadium4]

Just had my car inspection last night, the CO came out 6.9 out of 10 (NYC) For some reason its double of last year.. the past few year has been the same around 2.0 - 2.5. Car is 99.. where should I check first ?

 

[blahblah99]

Do you have high HC readings also? If so, your car may be running rich.

The first thing to try is replacing your O2 sensor.

 

[Carbonadium4]

I dont have my slip with me, but HC used to be .07, its now 1.69 i think..

Running rich means too much fuel right ?

 

[Pacfanweb]

If they're both high, you're probably running rich. Usually, a rich condition runs the HC up first.
CO can be high for other reasons.