I took my car to be inspected and right as I put in the engine light came on. He put in a new oxygen sensor but now the monitors wont reset in the computer it has been two weeks. What can I do?

I can't be specific to your car but generally speaking, the computers in cars are VERY sensitive to changes in their sensors. Especially ones that sense chemical changes. I would venture a guess that your voltage readings changed between "ON" and "RUNNING" because the oxygen levels changed between a static reading with "ON" and an active, ever changing reading while "RUNNING" No two drops of anything are the same. Especially gasoline. This is why the O2 sensor takes a multitude of readings every second and tells the computer how to micro manage fuel allocation just as often. When I said that no two drops of anything are the same, this goes for everything else. The, probably original, O2 sensors that you took out were programmed into your computer at the factory. When you changed them, even if you bought them at Nissan, when your computer first "saw" them it was probably thinking, "Hey, whose these two new guys and do they know what they're talking about?" I would call Nissan and tell them your story and ask if your ECM, (Engine Control Module), needs to be reset or reprogrammed to recognize the new parts. Good luck.

Real simple

None of the shops you went to,
know how to diagnose a vehicle

I think your statement about one monitor,
is the evap system ,because they can test
the gas cap,the others have to run clear,
at least in New Jersey

Almost seems like the people that come to this site

Your shop just throw parts at the codes & no testing
to find a problem

If the problems are solved, you don't have to clear the codes

Clearing the MIL Lamp or check engine light, clears all data,
emission monitors,& freeze frame data set at the time fault
codes are set,so you got nothing to work with to find a problem

So never clear fault codes after a repair,let the monitors do their thing

All sensors are aftermarket sensors-so that is nonsense

That should have been a clue to forget that shop

The same companies make sensors for everyone,
new vehicle or used

Vehicle manufactures stamp sheet steel & make bodies
& assemble purchased components only

No such thing as resetting those sensors

If the Oxygen Sensors work, the check light on the
dash will go out when the Emissions Monitors Run
for that system

You have 8 I/M Monitors that have to run clear before
you can go to inspection

Have a shop road test with scan tool to check that & make
the required repairs

make sure there is not a evedent eng. noise 1st

Replace oxygen sensors and have OBII scan at any good parts store and they can reset light door you. They do the scan free

either reset the computer or get a diagnostic scan to find the problem. the check engine light on doesn't mean it won't pass inspection

U have to operate the engine at all kinds of diff speeds and drive modes, it is called a OBDII drive cycle, here is how u do one.
1. As soon as the engine starts, idle the engine in drive for two and a half minutes with the A/C and rear defrost on. OBDII checks oxygen sensor heater circuits, air pump and EVAP purge.

2. Turn the A/C and rear defrost off, and accelerate to 55 mph at half throttle. OBDII checks for ignition misfire, fuel trim and canister purge.

3. Hold at a steady state speed of 55 mph for three minutes.

OBDII monitors EGR, air pump, O2 sensors and canister purge.

4. Decelerate (coast down) to 20 mph without braking or depressing the clutch. OBDII checks EGR and purge functions.

5. Accelerate back to 55 to 60 mph at half throttle. OBDII checks misfire, fuel trim and purge again.

6. Hold at a steady speed of 55 to 60 mph for five minutes.

OBDII monitors catalytic converter efficiency, misfire, EGR, fuel trim, oxygen sensors and purge functions.

7. Decelerate (coast down) to a stop without braking. OBDII makes a final check of EGR and canister purge

It sounds like you have either a lean or rich condition ocurring,could be exuast leak,vac leak,leaking fuel preasure regulator,cat convertor.At this point would go to dealer for diagnosis.

if you had it replaced it should have already been set however you can reset your cars computer by taking the positive battery cable off the battery and waiting 2-3 min and then touching the positive cable from the car to the negative cable which is still attached to the neg post on the battery for about 5 sec and the hooking it back up. that will reset the computer which would configure any new sensors. when the computer reads a bad code it bypasses that sensor so your car will run. it wont run to the best of its ability though - that's why you didn't pass an inspection. when you replaced the sensor the computer didn't notice because it already stopped reading that sensor when it went bad and doesnt know about the new one. when you reset the computer as i told you then it will read the new sensor and work properly.

Autozone oxygen sensors do not function properly in Toyota vehicles. Just had a Tacoma yesterday with the same issue. New sensors, runs poor, check engine light on. Toyota sensors fixed it right now.