Hi there, sorry your having problems.
I will be happy to help you with this problem.
You can get this code for a couple different reasons. The most common being either an intake air leak or a leak at the exhaust manifold.
If the intake is leaking it should be relatively cheap to repair, with parts and labor a couple hundred dollars.
If the exhaust manifold catalyst is cracked and leaking it will run about $850.
So the first step here is checking for air or exhaust leaks to see if they are present and if not just replace the oxygen sensor, but ideally it's almost always an air leak.
Let me know how else I can help please.