can you should me were on the car are the oxgyen senors all 4 I don't know where on 2004 Cadillac DeVille

can I get a picture of where they are

2 answers 6 comments
why are you replacing them?? the chances of all 4 failing at the same time is like you getting hit by lightning in your living room.

what is the issue??

Roy
or could it be the mass air flow senor
ok, same question, what is the issue???
Roy
service engine soon light stays on
what is the code??

Roy
po171 and po174
Those codes tell you the sensors are working . diagnose the CAUSE before replacing parts .
if the service engine light is on have it scan tested for codes