I have an '83 pickup, bought it about a year ago in California, where it spent it whole life. 6 months ago I moved to Colorado and this is the first time it has experience a real winter.

OK so two things

One, when I'm sitting at idle with my lights on and I turn the lights to parking lights only, the engine starts running rougher, and then when I turn the lights off completely it gets even worse.

Two, when I'm driving and I take my foot of the gas with the truck in gear I hear a sputtering noise. If I hit the gas again or engage the clutch it goes away. The noise is worse when the truck is cold but still there when fully warmed up.

Thanks for any ideas or advice