2002 Oldsmobile Alero 2.2L engine.

Warning lights = Service Vehicle Soon
Ignition Module was recently replaced
I have 2 questions.. The first is that whenever I manually turn my headlamps on or they come on at night, the Service Vehicle Soon light comes on.

The headlamps work fine, but the light comes on every time the headlamps come on.
The second question I have is that my car sputters/misfires once the engine has warmed up. It idles rough and sputters when I hit the gas from stop. I have a sound system and I turned down my Amplifier and it seems to have helped the severity of the sputtering, but it still does it. I had the ignition module replaced a few months ago. Any suggestions? Thanks!

Answer: The service vehicle light may be on because of a bulb out. Possibly a marker light or a DRL. If your DRL system is not working, the resistor may be blown. Can't think of any correlation between the engine misfire and the amplifier. Check the spark plugs. The ignition coil housing may also be the problem. This is the housing on top of the engine that houses the ignition coils. Can be a little difficult to diagnose. Another possibility is a carbon problem on the valves. A compression test would need to be done to check for this.