Failed Ohio Echeck

[92BMW318is]

High (CO) rating on emissions test

Limit: 0.65
Reading: 1.83
Fail

(NO)
Limit: 821.0
Reading: 397.4
Pass

(HC)
Limit: 117.0
Reading: 94.0
Pass

(CO2)
Limit: N/A
Reading: 13.50
N/A



Soo is there any cheap fixes for this, like some kind of fuel treatment that will raise the probability of the car passing.

2 more checks before i have to start paying...

[DesktopDave]

Usually high CO is a rich mixture.  I'm not sure about Ohio's testing regimen...but I'd do the usual...check O2 sensor, air filter, ICV, CCV (if you have one), AFM, coolant temp sensor, etc.