2005 Nissan Sentra • 4 cylinder FWD Automatic • 90 miles

I have a 2005 Nissan Sentra 1.8 that has a problem with the engine. First, the engine sounds alright when I start it, but driving it is a different matter. It sounds like the engine needs a timing check, sputters while driving and there is white smoke that smells a little metallic. Is there a sensor problem? Or is there something going on with the valves (sticking?). I'd appreciate any help on the matter.
June 18, 2011.

Check the timing and verify that it within specs. Your engine is a distributorless type, so ignition timing is controlled by the computer. Verify the air gaps on the crank and cam sensors are properly set. Crank position sensor is F52 and camshaft sensor is F16.
Take the car to an Autozone or PepBoys and have them scan the computer for trouble codes, if any are present and let us know what they are.

Jun 18, 2011.
When was a tune-up last performed? Have the spark plugs checked. The smoke ans sputtering indicates a possible misfiring.

Jun 19, 2011.