CO and emissions

I failed emissions because of too much CO. I understand a new catalytic converter may be in order, but are there other options or possible causes that I might try?

its an '89 laredo.

Thanks

New thermostat, can of GOOD injection cleaner (BG's 44K) and an oil change will probably help a lot. I have no cat on mine and it passes the sniff test just fine!

High CO is often caused by a rich fuel mixture. Do they test your vehicle JUST at idle or is there an acceleration test too? Some things that can contribute to high CO level include a failing oxygen sensor, excessive fuel pressure (check pressure at rail/compare to spec), and leaky fuel injectors. Some things to think about....