: PCM codes P0138 and P1139

05-09-09, 06:42 AM
I replaced the o2 sensor before the catylitic convertor just had four wires no plug adaptor don't know if we wired it corrrectley. Any suggestions. What do I need to do to stop these codes from coming up. I know hw to clear the codes. Thanks.

05-09-09, 01:09 PM
Both codes refer to the pre-cat O2 sensor.....If you had a replacement with no connector and soldered the wires, it's possible that something's crossed.....you'll need to get a factory service manual by Helm (www.helminc.com or try eBay.) The service manual for my 02 cautions against soldering connections or kinking wires for O2 sensors - something to do with resistances and a ground "clean air reference".

05-09-09, 04:30 PM
You cannot solder the wires on an O2 sensor. It won't work if you do. Ewill3rd once explained why.

05-10-09, 08:33 AM
What do i nned to do now? We clipped off the clip coming from the motor and threw it away. We spiced the wires together. Any suggestions greatly appreciated. I need to get this resolved trying to sell the vehicle.

05-10-09, 09:18 AM
Find a wiring diagram for your car/engine. Try to connect the wires according to the diagram, using either butt connectors with a proper crimp or solder connections with heat shrink tubing. If that doesn't work find the proper wiring harness with connector, at a junkyard, and replace the harness and O2 sensor with pieces with the proper connectors. If that doesn't work, dealer. $$$$$.

Kicker is that you cannot sell a car without OEM emissions equipment working.

05-10-09, 09:35 AM
Any sugestions on finding the wiring diagram for a 1997 Seville SLS. Thanks.

05-10-09, 10:03 AM
Google or www.alldatadiy.com

Somewhere in Technical Tips there's a link to a midwest library that has an impressive set of manuals online.

05-10-09, 04:56 PM
Standby. I'll PM Ewill and have him stop by. You need to use a certain type of connector to repair it. He covered that too once before.

05-10-09, 08:49 PM
Thanks I'm new to this and this site has been great help. I' ll be wating for his response. One again thanks for everyones help. Keep up the good work.

05-11-09, 07:55 AM
O2 sensors actually "breathe" through the wires. If you solder the wires you cut off an air path and it can affect the operation of the sensor.
For this type of repair you need a "crimp and seal" type butt splice connection.
We have a lot of them in the dealership here but I am not sure where you can get them otherwise.
Go to a Cadillac dealer and ask for part number 12089189. Get two of them, that should get you 6 of the splice sleeves.
Use a crimper that will not damage the insulation and then use a heat gun or torch with a ceramic element (not a flame) to seal them from the center out.
They are filled with a hot glue type sealer. This will seal the connection from weather but allow the wires to breathe.
As for the wiring, you shouldn't have cut the wires off because now you have a mess. I can't really tell you what to do because often the sensor will have two black wires and with no connector there is no real way to tell which is which. It is important to wire it right.
You might be able to use an ohm meter to pair the wires with eachother. The heater circuit should have much lower resistance than the sensor circuit.