[Shane@DBPerformance]

Check the air temp compensation table and try adjusting it versus the air temps you are seeing. With no air temp correction at all, it should run richer when it's hot and leaner when it's cold. If it is way over compensating(too much fuel) in the air temp table for colder temps then try lowering it down some at that temperature. Going from 14-15s to 12s though seems like way too much though for the kind of values you normally see in the air temp table. Make sure your air temp sensor or coolant temp sensor hasn't failed and inturn giving extremely cold readings to the AEM and making it run really rich.