I've got a few out of the way areas to test drive, but it's kind of hard to accurately test WOT conditions with winter streets/roads since they tend to have a bit of sand on them!!!! :steering:
If those AFRs are at the begining of WOT, I wouldn't worry about it. It takes a bit to stablize. Just read a post where a guy said he couldn't fix it with a key pad. So its not just carbs. LOL
Not the best example but shows the idea. After the shift into higher gear and the load was higher the AFR stabilized.