Error Code Help

94fiveptslow said:

Just a thought...but i thought i would ask anyways...if your o2's are sending a signal to the computer that your running lean/rich doesnt that mean that there working to even give a reading??? Because correct me if im wrong..the o2's cant directly cut/add fuel..they tell the computer to do it, so..if there working enough for codes then there WORKING...right or wrong???...just curious....THANKS

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The thing about any sensor is they degrade over time. Just because a sensor is "working at all" doesn't mean it's working correctly. Here is an example.

If the wires on the MAF sensor get dirty, they will still provide a certain resistance per amount of air coming in, but the resistance will be wrong, so the computer will add/remove the wrong amount of fuel.

Now, onto your car. Once the car warms up, the computer begins to add/trim fuel based on the o2 sensors readings. Basically, the computer forces an oscillating rich/lean condition. Once the O2 reads a lean condition, the computer adds fuel until the O2 reads rich, then the computer removes fuel, until the computer reads lean again. This cycle repeats, and this maintains a a/f ratio around 14.7:1.

There is a specific O2 sensor resistance value that equates to this 14.7:1 ratio. So if the O2 sensors are somewhat degraded, the computer will be oscillating around an incorrect a/f ratio.

Once the car is warm, the computer assumes the O2 sensors are working properly, and only uses them to meter air. However, if the other sensors are reading way too high/low of air, compared to what the O2 sensors tell the computer, then the computer spits out codes.

You read the codes wrong in your first post.

172/173 means the passenger side O2 is reading both a lean and rich condition. 176 means the drivers side O2 indicates lean.

My guess is another sensor is bad, and the O2 sensors are telling you this.

Do a search on here for how to clean your MAF/IAT sensors & check your fuel pressure. You also may want to check/replace your spark plugs/cap/rotor (although probably not the problem).
Scott