Auto Parts: 99 Dodge neon DOHC check engine light, scanner obd2, oxygen sensors

Question
HI Mike
how are you
my name is Gabi and i got 99 Dodge neon DOHC 97000 mi
today the check engine light went on and i need to check the code of the problem so will this item be compatible and can you tell me where is the connector located?
but i still believe the problem is fuel mixture because the day the check engine went on i used FUEL SYSTEM CLEANER and that was for the third time through the last 3000 miles i putted on the car So could that be the problem that caused the check engine light on
I'm sorry for talking a lot and here the link is:
http://cgi.ebay.com/ebaymotors/Car-Scanner-OBD2-CHECK-ENGINE-LIGHT-CODE-READER-O...


Thanks a lot
Sincerely
G.Koussa

Answer
    That item will give you the code, then you can google the code to find out what it is.  It is highly unlikely that any sort of fuel system cleaner could cause the engine to throw a code.  Unless you used a product not intended for automobiles and it somehow damaged the oxygen sensor, then it would light up the light when the sensor failed.  That is why OBDII cars have two oxygen sensors: if one fails, the reading from the other one confirms it.  Older cars that had only one oxygen sensor couldn't tell whether the sensor was bad or just not heated up yet.  That looks like a decent price for a code reader, although I would shop around anyway; you're probably only going to use this thing once.