Help Needed with O2's
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TECH Enthusiast
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Joined: Jan 2003
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From: Cape Coral, FL
Help Needed with O2's I was looking at my O2's at WOT the other day. I just installed my headers and got my LTrims under control. My bank 1 O2 is a ~1.050 at WOT and my bank 2 is at like ~.94. Arent they both suposed to be about equal? Could one of my cylinders not be working properly making the one side of the engine a little rich? I know I need to lean the WOT out a bit but why are my O2's so different? I checked and I have no misfires and it idles very smooth. Just wondering if one of my O2's is messed up or what. thanks for you help.
Both of those numbers are pig rich. The difference probably
lies more in temperature(differences in location and heat
loss) than mixture.
lies more in temperature(differences in location and heat
loss) than mixture.
Originally Posted by TransAmJo
I was looking at my O2's at WOT the other day. I just installed my headers and got my LTrims under control. My bank 1 O2 is a ~1.050 at WOT and my bank 2 is at like ~.94. Arent they both suposed to be about equal? Could one of my cylinders not be working properly making the one side of the engine a little rich? I know I need to lean the WOT out a bit but why are my O2's so different? I checked and I have no misfires and it idles very smooth. Just wondering if one of my O2's is messed up or what. thanks for you help.
TECH Senior Member
Joined: Nov 2001
Posts: 9,246
Likes: 3
From: Troy, AL
Your car's O2 sensors were not designed to read mixtures that rich. The two banks are probably not as far off from one another as you might think. It could also be a difference in fuel pressure from one rail to another. It could be a difference in O2s (they vary...especially outside of the stoic range.) And, like Jimmy said, it could simply be O2 sensor location.
But, the first thing you need to do is lean that sucker back down. They may become closer together after that.
Hint: Make sure you don't have an exhaust leak. Outside air coming into contact with the O2 sensors can also cause this problem. This often happens when people try to run open headers without using header extensions. The problem of O2 sensors coming into contact with outside air will be reflected in your Ltrim readings which will be well on the positive side.
But, the first thing you need to do is lean that sucker back down. They may become closer together after that.
Hint: Make sure you don't have an exhaust leak. Outside air coming into contact with the O2 sensors can also cause this problem. This often happens when people try to run open headers without using header extensions. The problem of O2 sensors coming into contact with outside air will be reflected in your Ltrim readings which will be well on the positive side.
