Still getting P0138 after replacing o2 sensor

[ballsie]

We got a new car and Im trying to sell the 1999.5 Pathfinder. The SES light turned on a couple days ago and it was P0138.

High voltage Bank 1 Sensor 2.

I replaced the driver side bottom (after the cat) o2 sensor and pulled the battery for about 30 minutes. Light was off for 3 days and now its on again with the same code/same o2 sensor.

What gives? Anyone seen this before?

[smj999smj]

There was a Nissan service bulletin regarding O2 sensors codes on 96-00 Pathfinders. It was bulletin #NTB99-004B. It basically involved a poor ground of the EGI harness at the the two ground points on top of the intake plenum. There's a subharness available that provides a supplemental ground from those points to the side of the right bank cylinder head. Refer to the bulletin for more info.

[ballsie]

Thanks! I just ordered the harness. Does anyone know of a write up on the installation procedure? I heard its pretty easy, but Id like to have an idea on what I'm doing before I get started.

[smj999smj]

It's simple. Unbolt the two ground screws from the intake plenum that secure the EGI harness grounds to it. Get a little sandpaper and clean up the ground eyelets and contact surface on the intake. Route the new sub-harness from the ground points on the plenum to the front of the engine and over to the front of the right bank cylinder head. On the side of the head there are a couple of 8mm threaded holes. The two bolts you order with the harness go through the eyelets of the harness and thread into those holes in the head. Reinstall the plenum bolts through the EGI harness grounds and through the subharness eyelets. Secure the subharness with wire ties. It's nothing high-tech. Erase your codes. For more details and illustrations, refer to the TSB if needed.

[ballsie]

I just installed the harness that I paid $116 for, but could have made it for about $1.

Check the pics and let me know if I installed it in the correct location. I am not positice where the EGI (EGR) harness mounts.

Did I do this right? The SES light is still on, so I disconnected the battery and Im letting it sit for a while.

[smj999smj]

You have the top side (the one with the smaller eyelets) mounted in the wrong place. Look more towards the passenger side of the upper plenum (from where you have currently installed the harness). You will see two 10MM bolt heads next to each other with wires going to them; refer to Nissan service bulletin #NTB99-004B, which will have a picture of the EGI harness grounds. You can probably find a copy of the bulletin in the "knowledge base" at NissanHelp.com. Also, disconnecting the battery might turn the light off, but it does not erase the code from the ECM. You will have to use a code reader, scantool or erase it manually via the ECM mode screw. Try troublecodes.net/Nissan for the manual method.

[smj999smj]

Try this link:

http://www.alldatadiy.com/techtips/ALLD ... 91031.html

[slopoke]

Bank 1 is the passenger's side of the vehicle, Bank 2 is driver's. Also sjm is right there are multiple TSBs regarding this. depending on the VIN you may also need to have the ecm reflashed with the latest calibrations. edit: TSB#NTB01-048A from Mar 13 2002

[smj999smj]

If it's a 99.5, it would have a reprogrammable ECM, so that bulletin may apply as well:

http://x.nissanhelp.com/forums/Knowledg ... ghgrH8kzAM

[ballsie]

Thanks guys, That is what I needed. SES light is still on, so I will move it to the correct location.

[fixinto]

Bank 1 is the passenger's side of the vehicle, Bank 2 is driver's. Also sjm is right there are multiple TSBs regarding this. depending on the VIN you may also need to have the ecm reflashed with the latest calibrations. edit: TSB#NTB01-048A from Mar 13 2002

X2 bank one is always where the number one sparkplug is located. Change the other O2 and u should be good to go.