Question about o2 sensors
Thread Starter
Staging Lane
Joined: Apr 2005
Posts: 59
Likes: 0
From: Pittsburgh, PA
Question about o2 sensors My SES light came on, I got the codes read and it returned 2 bad o2 sensors (one in front, one in back) I have heard not to worry about the back ones when it comes to performance. Another problem I have been encountering is very poor gas mileage and sub-par performance all around. I have pulled a spark plug out and they seem healthy. Do you guys think two new upfront oxygen sensors will solve my worries? Oh as well, Currently my ses light is off...not sure how...
11 Second Club
Joined: Feb 2003
Posts: 5,524
Likes: 1
From: The South
Sounds like the O2's are going, you are probably running rich. Does it idle rougher and kind of chug along at light throttle and low RPM? Maybe on and off in terms of being noticeable? Do you have any mods? (headers specifically) Replacing the front O2's is probably the way to go.
I had that problem recently. It happens a lot when you have headers. I replaced my sensors with ones meant for the rear bank on a C5. They work better with headers as they are made to be that far from the engine. Mine was an intermittent problem both in the SES light coming on and off and the performance being horribly bad then better. Sometimes it would act right with the light on, sometimes it would act like **** without the light off. Put new O2's in=instant fix. I got 7.8 mpg on a tank where the O2's were **** for most of it.
I had that problem recently. It happens a lot when you have headers. I replaced my sensors with ones meant for the rear bank on a C5. They work better with headers as they are made to be that far from the engine. Mine was an intermittent problem both in the SES light coming on and off and the performance being horribly bad then better. Sometimes it would act right with the light on, sometimes it would act like **** without the light off. Put new O2's in=instant fix. I got 7.8 mpg on a tank where the O2's were **** for most of it.
Thread Starter
Staging Lane
Joined: Apr 2005
Posts: 59
Likes: 0
From: Pittsburgh, PA
Being the cheap-*** I am, Should I just replace the fronts being that the front ones are the only ones that the computer uses to figure out fuel? I am hoping this also fixes the weird hesitation the car has under different kinds of acceleration, as well as my utterly terrible gas mileage (like 11 mpg! 
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