emissions error codes

2001 OLDSMOBILE ALERO
159,000 MILES • 3.4L • 6 CYL • 2WD • AUTOMATIC
Avatar
DANE DESPAW SR.
  • MEMBER
  • 75 POSTS
Okay, getting codes P0131, P0135. Have changed O2 sensors and c-converter. Still getting the same codes, and getting them as pending as well. This is making me assume I have a wiring or connector problem. I have checked these and they look good, but? The car also keeps having the security light come on and when it does, the car will not start without clearing that out. I replaced the computer, (with a used one from a different make and model car) but the problem keeps re-occurring. I talked to a mechanic about re programming the computer. He said he would be happy to do it, but said that I would be wasting my money. So now the million dollar question: What in God's name do I need to do to fix this?
Nov 5, 2017 at 8:51 AM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
With both of those codes together it sounds like a wiring problem. I assume you changed all of the sensors? I would start by checking the wiring/connections here is a guide to show you how to do it and some engine wiring diagrams for the oxygen sensors.

https://www.2carpros.com/articles/how-to-check-wiring

Please run some tests and get back to us.

Cheers, Ken
Nov 6, 2017 at 2:26 PM
Avatar
DANE DESPAW SR.
  • MEMBER
  • 75 POSTS
Thank you for your response. This morning was the first chance I've had to look at the car again. The wiring connector at the O2 sensor right behind the engine seems to be backwards. The locking tabs are on opposite sides (don't line up) (see picture). This is the O2 sensor showing in the error codes, so the new question is, is it likely that this is the wrong O2 sensor for the car? Can I take the connector apart and move the wiring to where it needs to be?
Nov 12, 2017 at 8:22 AM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
Good find it look like someone has installed the incorrect oxygen sensor. Please replace the sensor with the correct unit.

Here is a guide to help you get the job done.

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

Please let us know what happens.

Cheers, Ken
Nov 13, 2017 at 9:07 AM
Avatar
DANE DESPAW SR.
  • MEMBER
  • 75 POSTS
Alright. Thank you for your assistance in this matter... Will let you know what happens
Nov 13, 2017 at 3:45 PM
Avatar
DANE DESPAW SR.
  • MEMBER
  • 75 POSTS
is that position considered upstream or downstream?
Nov 13, 2017 at 3:54 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
If the sensor is after the catalytic converter it is down stream.
Nov 14, 2017 at 9:43 AM