CO too high for emissions

[AZJETSFAN]

I really could use some help with this problem. I have a new catalytic converter, new bosch iridium IX spark plugs, the distributor cap, ignition rotor, and wires a fairly new. I just replaced the head gasket. As for the timing belt, I replaced it 5 months ago and using a timing light on it, it checks out fine. The oxygen sensor is only a year old. The car runs beautiful with no check engine light. Any help you can provide will be greatly appreciated.

 

[staytrue2007]

High CO means you are not burning all the fuel during combustion. Here is a sight that will steer you in the right direction. Diagnose Emission Test Failure – Auto Repair Help

 

[motomattx]

Valve seals?