Mitsubishi Repair: service engine light, mitsubishi galant, code scanner

Question
i have a 2001 mitsubishi galant, automatic with a 4 cyl engine. it has a bit over 41000 miles on it. the service engine light recently came on and eventually went away by itself. two days ago it came on again and has stayed on since. i don't have a code scanner but would like to fix it myself. my question is, what are the most likely problems to cause the service engine light to go on and stay on? any help would be appreciated. thanks, jim    

p.s.  i have noticed recently that the engine hesitates or stumbles a bit when starting off from a stop.  

Answer
Jim,
Hesitation problems are usually caused by worn ignition components, fuel components, and emission components.  Your 'service engine soon' comes on typically for problems it detects in the ignition or emissions system.  Ignition components that may be at fault can include spark plugs, spark plug wires, distributor cap, and rotor.  All these items are considered to be 'regular maintenance items' and should be replaced every 30,000 miles or so (which means you're due if you've never replaced them).

Fuel components that may be at fault include mainly your fuel pump and fuel filter.  My guess is that your pump is fine, but your fuel filter is a bit clogged.  The fuel filter is a regular maintenance item as well, and should be replaced every couple years or 30,000 miles.  

Next item you'll want to consider replacing soon is your timing belt.  That typically is replaced every 60,000 miles.  You're not there yet, but you should keep it in mind.  

If you have an AutoZone in your area, they will happily check your car's computer with their code scanner for free.  This is a great service that is definitely worth using.  Just walk in and tell them your check engine light is on and you'd like them to scan it.  They will scan it and decipher any codes they find.  If you were to get this done at a garage or the dealership, it would cost your around $80.  

Once you get the codes, contact your local dealership and ask them if the items found by AutoZone's scan read are covered under your warranty.  Your car came with a standard drivetrain warranty of 5 yr./60,000 mi.  So, you're definitely in range.  There's a good chance whatever the problem is, your warranty may still cover it.
Good luck!