P0138 fault code

[MJRAD]

I have a 2005 Pontiac Vibe AWD with 302,000 KM on it. It is starting to throw P0138 fault codes. From the research that I have done on the Internet, it looks like this is the oxygen sensor on the catalytic converter. Is this correct? If so, it looks like the wiring harness disconnect is under the carpet on the front passenger floor. How do you access the connector? Do you have to remove the door sill trim panel first or can you remove push in clips by center console and roll carpet back? Do you need a special tool to remove the sensor? If somebody has done this and could comment or provide links with pictures, it would be greatly appreciated. Also part number and where you bought it would be nice as well. Thanks.

[joatmon]

I agree, P0138 is the code for a bad O2 sensor, the one under the car near the cat.

There's no reason to remove any trim pieces. I haven't done it for a while, but I think there are one or two plastic push pins that tack the carpet to the center hump, you should be able to pry these out with a screw driver, or a pair of needle nose pliers, Then just pull the carpet down from the top to expose the connector



Disconnect the connector, and push the rubber grommet and wire through the floor pan.

No particular special tool needed to remove the O2 sensor from the pipe. They sell special "O2 Sensor Sockets" and the sensor is a metric size, maybe 22mm, but what I did was take a 7/8 closed end wrench because that's what I had, worked it up the cable and past the rubber grommet. I have also taken them out using a large adjustable crescent wrench. Just make sure it's a good fit, because after so many years and the high heat, the thing will be sort of rusted into place, so you might need to smack the tool with something heavy, like a hammer or a rock, to break the rust. It has standard orientation threads, so make sure you smack it the right direction (to turn it counter clockwise in this picture)



I bought one form one of the chain auto parts stores, Advance Auto or Autozone, but don't remember the part number. Might be different part for base/GT/AWD, but don't remember.

[joatmon]

As you IM'd me, the routing in your AWD vibe is different than in the pictures from a base that I posted. If the connector is close to the door, probably best to go in from the door side. I've never pulled that trim piece, but I'd go with sidenshowalan's response in forums.genvibe.com/phpBB3/viewtopic.php?f=29&t=43940

[MJRAD]

Thanks for your help. I changed the O2 sensor and everything is working well. No more P0138 codes. Thought I would post what I found when installing the sensor so it can help somebody else out. If you have an AWD vibe(1st generation), the sensor connector is located under the passenger front seat. Just remove the 4 bolts holding the seat to the floor and take out the seat. Then you can access the connector easily. Nothing else has to be removed.

[Salsa Guy]

AWESOME!