P0138! Front air/ratio censor not rear in most cases

hey everybody I just wanted to mention the results of a CEL LIGHT issue. Recentlythe check engine light came on my 2005 Prius(162000 miles). Got the code checked and it was p0-138. every mechanic and their mother calls out the rear oxygen sensor for this code. So I replaced the rear oxygen sensor and light was still on. after digging deep I found a few people having the same issue but not posting the end result after going to the dealership. so finally I found a thread posted their end result and it turned out to be the front air/fuel ratio oxygen sensor. apparently with other makes it usually is the rear but with Toyotas it is usually the front. so sure enough I replaced the front sensor and problem solved. hopefully this can save somebody a lot of grief in diagnosing p0 138