Originally Posted by Jbrew

User mbb posted 4 links that would answer that real quick, - I guess you missed all of them lol. If that was to overwhelming, just look up the DTC (PO141) in the DTC lists. It's stickied near the top of the thread list. Might as well do that, it'll make it easier the next time. I think the DTC list is the 4th thread down.

Also, it's best to replace BOTH upstream O2's at the same time. Bank 1 and 2 upstream O2's.