Infiniti G20 HC an CO failing on emission

[Lady Bella]

Hello I am looking at buying a used 1993 G20. First I want to know if it's worth buying because it passed everything but the HC and CO test when i took it to get the emissions done. What could be causing this to happen? Please someone help.

[Q451990]

to NICO!

Sadly, I have no idea what elevated numbers in those categories mean. Hopefully someone else will come along with something more specific.

Here's what I came up with from a Google search:

Elevated hydrocarbon (HC) emissions usually indicate ignition misfire due to fouled spark plugs or a bad plug. But high HC emissions can also be caused by burned exhaust valves (check compression), lean misfire (check for vacuum leaks, low fuel pressure or dirty injectors), or rich fuel conditions (fuel saturated carburetor floats, excessive fuel pressure, leaky injectors or a dead O2 sensor).

High carbon monoxide (CO) emissions are a telltale sign of a rich fuel mixture. On older carbureted vehicles, fuel-saturated plastic floats, incorrect float settings, leaky power valves and misadjusted chokes are often responsible for the rich mixture. On newer vehicles with feedback fuel controls and fuel injection, leaky injectors, excessive fuel pressure and sluggish or contaminated O2 sensors are all possibilities to investigate.

I suspect it's pretty generic information, but maybe it's a start?

Heath