Jump to content
CaddyInfo Cadillac Forum

need help with oxygen sensor codes


Recommended Posts

I've got codes P0137, P0139, P0151 & P0171.

They're all history but my service engine soon light is on.

Is there 3 or 4 sensors on the caddy?

Since the codes indicate a problem with more then one sensor would it be best to replace all 3 or 4 of them at the same time?


Link to comment
Share on other sites

There are 4 sensors.

Bank 2 sensor 1 - left (front) manifold

Bank 1 sensor 1 - right (firewall) manifold

Bank 1 sensor 2 - pre-cat (in the Y pipe I beleive)

Bank 1 sensor 3 - aft-cat

If they are history I would clear the codes and ignor them. See if they come back.

More importantly I doubt all 4 would go bad at the same time unless you are the unluckiest guy in the world, in which case I would quit driving :lol: Most likely you are running too rich or too lean causing all 4 to set a code (unless you sparyed silicone into the intake). Check the FPR to see if it's leaking. Check for leaking injectors.

Link to comment
Share on other sites

Thanks Larry.

I will clear the codes and check out the engine.

I'm not sure how you clear the codes. I did a search but the new board doesn't seem to have the info the old board did.

I also have code IRC B1740 History. I looked thru my GM service manual and couldn't find anything. The GM SM isn't very easy to find info sometimes or is it just me? :)

Link to comment
Share on other sites

No it's not you. Ever since they redesigned those manuals I have a hell of a time trying to find things. Sometimes it is in 2 or 3 different places.

After you get the codes it will ask "PCM?" Use the LOW fan speed for no and HI fan speed for yes. Answer yes to "PCM?" Then answer no til you get to "CLEAR CODES?" Obviously answer yes to that one. Then exit system by pressing........ahh, I forget, OFF I think but you can always just turn the key off.

Link to comment
Share on other sites

  • 4 months later...


This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...