Chrysler Repair: 99 TOWN & COUNTRY check engine light,: mileage dropped, oxygen sensors, code translation

Question
MY CHECK ENGINE LIGHT CAME ON AND MY GAS MILAGE DROPPED TERRIBLY. CAN YOU HELP PLEASE  

Answer
Hi Andy,
The best clue is to get the engine controller memory to tell you what fault code it has noted, then translate the code for the specific answer. One place that will probably do this for free is an Autozone store or similar parts chain. You can find a shop that has a code reader who will do it for around $40.
You may be able to get the code by turning the ignition switch "on-off-on-off-on and leave on" within a 5 second elapsed time or less. Then watch the odometer window to see if a code "P----" appears or several such codes.
You can get a code translation at www.allpar.com/fix/codes.html
Or write back and tell me what the codes are.
Usually when the mileage drops it is related to the mixture and that is often due to one of the oxygen sensors failing. The code will tell you if that is the case, and which of the sensors is bad.
So one way or the other, get the codes readout and write me back. If I'm maxed out use the "thank and rate" tab below and leave a comment as to what you found out. I get an alert and will write back to you.
Roland