In all likelyhood, the catalyst was probably just too cold. Ignition problems will usually cause high HC while CO is low. Your first CO readings indicate that the catalyst was doing virtually nothing. With no catalyst and a functioning lambda system the CO will be about 0.5 percent.

"Conditioning" makes a HUGE difference, particularly on older cars that have some catalyst degradation.

To those of you who have to have periodic emission tests, you must follow some basic rules to ensure that the catalyst is hot at the beginning of the test.

1. Never just take you car to a shop for an emission test, drop it off and pick it up later.

2. Thoroughly warm the car up with at least 20 minutes of driving, preferably including a freeway jaunt.

3. If at all possible, go to a "drive through" place (They are common in California.) They are like a car wash, you just line up behind one of the test bays and wait your turn. Come back if the line is more that two cars deep.

4. Keep the engine at about 1500 revs with the AC or defroster on so the compressor puts some load on the engine.

5. DO NOT SHUT THE ENGINE OFF WHILE YOU ARE WAITING!!!

Duke