Thanks' for the info but I'm not sure it's a winter blend gas issue as I have changed the air filter with a K&N. It's real sooty at the tail pipe
Why didn't you tell us before? The oil on the K&N filter probably contaminated the MAF , giving your rich condition, go to your local auto parts store and get some CRC MAF cleaner and check out some youtube videos on how to use it. It should clear up your issue.
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