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My wife has a 2006 SI coupe that's had a light on for a while of and on. I ran it last night because it stayed on all night so it was on when I passed a parts store. We ran he code and it shows "Running rich bank 1". It doesn't act up and doesn't smoke but it's using more gas than it needs to be. Thought I was gonna get off buying a part for a easy fix. What could this be?

 
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are there any other codes? could be something easy like oxygen sensor, but that should have its own code.

 
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May have been worded different and had a number before it. I looked at the screen when the parts guy ran the thing for codes and it threw "rich on bank 1" or along those lines and that's all it showed. Wouldn't narrow down a cause or reason for this.

 
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Yea I have a Dodge truck and it threw a code and showed "O2 sensor bank 1 right side" so they have their own code narrowing the exact place.