[woodman13]

I ran into a similar problem with a 6 cyl truck, I had done a complete tune up the week before. I changed the oil and filter, drove to the testing station the evening before and parked in the parking lot. The next day I was the first guy in line with my cold engine. By the time I finished the testing my loaded CO was within acceptable tolerance and I was barely up to operation temp. Don't know why, but I know it worked and I was driving my 67 Chevy LB with 6 cyl and 3 sp to work the same day all legal!