Chrysler Repair: 99 Sebring Convertible - Service Engine Soon light on, reputable repair shop, convertible service

Question
I read previous information about the EGR valve causing the service engine soon light to come on.  I'm wondering however, if my problem may be related to spark plug wires?  I'm not having any other symptoms other than the service engine soon light but the problem began shortly after a "shade tree guy" did a tune up on my car and changed spark plugs out...for a day or two the car did stall when I first cranked it and tried to shift out of drive but then it started running fine.  Now about 3 weeks later the service engine light is coming on.  I took it in to a reputable repair shop but the guy  indicated that his scanner could not communicate with my car.  Any ideas?

Answer
Hi Pam,
I would inquire of the shade tree guy as to exactly what parts of the engine and its electrical system he touched or changed. Then let me know that.
If you have an Autozone parts store near you I would go there and ask for a free readout of your powertrain memory via that plug that is under the dash near the steering wheel.
If you don't have such a store nearby, then I would try to find another shop that has a reader because getting that code stored in memory to reveal itself because that is a great shortcut to figuring out what is wrong. If you can't get a readout from an independent shop then try a dealer, though they may charge more. Let me know the code number, the code name, what they say needs to be done, and how much they will charge. Also ask if the readout cost would be deducted from the charge if you let them do the repair (ask this after they tell you the estimated repair cost). Then check back with me and we can compare that with the manuals I have.
Is there any other problem now with how the engine is running?
Roland