Upstream or downstream?
I don't know just trying to get the pass admission test but took the car to auto zone and computer said oxygen sensor
It should say something like, bank sensor 1 or bank 2 sensor 1 for upstream then bank 1sensor 2 or bank 2 sensor 2. For downstream.
so it had 2 sensors if I change both the check engine light should go out
It might or might not, you could have a fuel supply or pressure problem, map sensor could be out of specs. Ect reading high or low, there a number of things that can give you an O2 code, O2 sensors are common failures but just be aware that replacing the sensors might not be the fix.
The code(s) you got were likely "Lean" or "Rich" codes. They almost NEVER indicate a problem with the sensor but a problem with the SYSTEM. Just reading the code(s) and changing the part(s) isn't going to fix it. BTW - the people at Autozone are Retail Clerks - they don't know crap about cars - they're sales people.
all the things you guys are talking about is what the machine says so what I am trying to figure out is what is the problem
To save yourself a headache and skinned knuckles, I would advise you to take it to a shop that you trust and have the system checked, make sure they can do a "live data" test, that will show what all of the sensors are reading and the ECM's response, it might be a little expensive but you will save by not just replacing parts.
What you think it will cost?
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