Hi all-
I'm just getting started into auto mechanics, and I've got some pretty basic questions about the O2 sensors. My car has been throwing code P0153, which from what I've read on here means that I need to replace the O2's. So, how many of those things are there and where are they located? Also, are they very tough to get out (i.e. can I do it myself)? Do I need any special tools? Thanks for the help!

 

Your OBD-II engine has 4 O2 sensors.... two "pre-cat" that help the PCM control A/F ratio, and two "after-cat" that measure the effectiveness of the cats. P0153 is slow response, Bank 2 (right/passenger side), Sensor 1 (pre-cat). I think that one is on the Y-pipe, just below the connection to the exhaust manifold. A bit hard to reach. If it is corrded in place, can be a real dog to remove. There is a special "O2 sensor" socket that allows it to be placed over the sensor with the wire intact, but it takes a lot of room.

"Slow response" probably indicate the sensor itself is dieing. Replacement would be the best response at this point. Alternatively, you could swap the Bank 1 and Bank 2 pre-cat sensors and see if the problem follows the sensor (bad sensor) or stays on Bank 2 (something other than the sensor). But that might be more work than just changing it.

Use only AC/Delco OEM 4-wire sensor, available from online discount GM parts dealers (e.g. Jason Cromer, Dal Slabaugh) for about $35.

 

Wow, thanks for the info. I went out and looked under the hood, and I think I found the sensor, but I'm not sure. There were two (I think) white cylinder type things plugged into the piping right before the triangular connector that connects the exhaust manifold to the Y-Pipe. Is one of those it?

 

ttt, any help is appreciated!