Got back from a run to the Carolina Mountains on Tuesday. It was cold, lows around 30, highs around 55. After running for a hour or two, the check engine light would come on and stay on. While the engine light was on the cruse would not set. Once I got back to Florida and slowed to 50 and below, light went out and cruse worked fine. Also had soMe decel pop while in the mountains. Anyone ever seen this before? Can anyone tell me how to check my engine codes? My ride is a 08' SG with air cleaner, Thunder Headers and a Fuelpak.

 

check out this thread. there is detailed instructions in it on how to check your codes, and what they mean.
Ran out of gas now check engine light is on?? - Harley Davidson Forums

 

Very first thing I would do is **** can the Fuel-Pac. V&H makes a outstanding exhaust system.....but I think the Fuel-Pac sucks. Get yourself a good fuel management system....dyno or not....and you will be happy!