Which O2 sensor is for my yukon

[mykon04]

The engine light came on in my 04 yukon with a 5.3 and I received the fault code P0174 and P0171 right and left bank so I believe that it is the two down stream o2 sensors.
I looked on Rock auto and I am not sure which one exactly to use. It seems some of the sensor ends that protrude into the exhaust are different. I have not pulled mine out to check exactly which one it looks like. I was trying to avoid this because once I pull one out I would like to put in a new one and only do this once. I have done some research and it is stated that they read off of the amount of voltage they (Create) and output up to .9volts? not real clear on that still reading though.

If anyone has any pics of theirs that they pulled out and changedwill you please PM me or post some pics. I appreciate the help.

 

[bermudablueZ71]

If both banks are reading lean it may not be both o2 sensors. Could be a vac leak or intake gaskets, etc. If you want to replace the sensors the section that goes into the exhaust doesn't really matter, only the proper connectors really matter.

 

[mykon04]

Bermuda thanks for the reply. I will do some more trouble shooting and check to see if it is a vacuum leak. I can just spray some carb cleaner around intake and vacuum fittings and listen for it to rev up right?

 

[bermudablueZ71]

Yeah that's right. The engine will either rev up or stall out a bit depending what product you use. Either way your looking for a change in idle speed based on introducing an un-metered foreign fuel to the mix.