I got this code today from my Dodge stratus with 76k miles and the code is P0137:

"Downstream and precat OS2 shorted to ground"

Any ideas on what I'm suppose to do? Do i just change the O2 sensors?

 

It's located somewhere on your exhaust pipe before your catalytic converter. pull it out and see if you have any obvious defects. if it's shorted to the tailpipe, or the wiring has chaffed against something, that could give you the signal. replace the sensor or fix the wiring. After the fix you need to get the check engine light turned off by a maintenance guy, unless you have a reset unit.

Let me know how it goes