Hyundai Repair: catalyic converter?, hyundai accent, catalytic converter

Question
I Have a 2000 Hyundai accent that I bought used in 2006. at first it was running smoothly but now I am having trouble with acceleration my engine light keeps coming on after I've had it repaired. the owner told me at first it was the catalytic converter but when I took it to the shop they told me it was my sensor, what is really the problem and where can I buy cheaper parts that don't break my pockets

Answer
The check engine lamp can come on for a large number of reasons.  Faults with any one of a number of sensors or with the catalytic converter are included in those reasons.

The fact that your check engine lamp continues to illuminate after repairs indicates that the vehicle either hasn't been repaired properly or there are additional problems occurring.

I can help you find the cause of the check engine lamp, but I'll need more information from you to do so.  For right now, I'll need to know what diagnostic trouble codes are stored.  AutoZone has advertised they'll check the trouble codes for free.  If you report back with the diagnostic trouble codes from the engine and transmission computers, I can advise you on what may be the cause and how to proceed with diagnosis.