What can I do to rid myself of a PO172 Bank 1 code on my 2002 Chevy venture?? on 2002 Chevrolet Venture

I know it means that the system is running too rich, and that the os sensors my need changing, I already done this, I need to know whats next to check to get rid of this code so I can get my van inspected. Many Many thanks

Asked by for the 2002 Chevrolet Venture
are you sure you adjusted the mixture of air to fuel as this is the only thing except you may be having a problem with a gasket on your intake manifold . This was a very common problem for this motor and the years 2001 - 2003. Check it again and or take it to one of the auto parts dealers that do the free check sometimes you just need to reset your computer which can be done bt disconnecting your fuse box under the hood for about 20 minutes and see if it comes on, as you said you repaired what it called for so they don't always reset automaticaly