Code reader gives code p0037 - o2 sensor bank one. Is bank 1 upstream or downstream? 1.6L Also how do you test an o2 sensor?

The P0037 code is for the heater element for the O2 sensor. Not sure if your car has one or not, but some vehicles have a separate fuse for heater; check your fuse box first. If nothing, then you'll need to replace the whole O2 sensor.

Is this a normal fuse in the main box? And if replacement is needed how do I know which one?

Do you have the owner's manual? That should list the fuses & their purposes. If a fuse is bad, the little metal piece inside of it will be broken; if it's good, the piece will still be intact.

Bank 1 is upstream. There's no need to worry about fuses, here. Here's how to replace the sensor:

https://www.askmehelpdesk.com/cars-t...tml#post223376

If you haven't contaminated the pigtail connector, the code is likely correct. Stay away from Bosch and other generic replacement sensors. Best to go with a Mazda replacement.

If the heater element has a separate fuse, then that should be checked prior to replacing the sensor. The element is what's setting the code.

Thanks for the help. What do you mean by "contaminated"? I'm trying to fix a problem that was not fixed properly before. One sensor was replaced with a universal but he did a rig job (bad connections). So then another guy fixed it "right" by soldering the wires. I don't have a separate fuse but checked them all with a test light to be sure. I don't now if the wires were fixed right but it was a cheap o2 sensor the never worked. I want to be sure whichoneisthrowing a code before I spend $225.00 for a new one.

What car has a separate fuse for the oxygen sensor's heater element? Never seen or heard of anything like that.

The heater just stabilizes the sensor's output. We are talking resistances of only 10 to 40 ohms.

If he rigged the wires, that's probably your whole problem.

Quote:

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Originally Posted by txgreasemonkey

What car has a separate fuse for the oxygen sensor's heater element? Never seen or heard of anything like that.

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'97 & up Cavaliers; in the fusebox located inside the driver's door paneling. Just as surprised as you were when I found that out!

It's imposible to do any soldering on an oxygen sensor and get away with it. It will throw a code forever. Differences (in millivolts) makes a difference, here.

After you replace the sensor with an OEM or OEM-equivalent, remember to reset the ECM.

Quote:

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Originally Posted by this8384

'97 & up Cavaliers; in the fusebox located inside the driver's door paneling. Just as surprised as you were when I found that out!

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I have never heard of that either. Does it list it in the owners manual? I guess I spend the money for a new one and start over. Thanks for the advice.

Finally replaced the O2 sensor, seems to run fine. How do I clear the computer without a scaner? I disconected the battery but the light came back on.

A simple code reader will do the trick. Many auto parts stores will do this for free.

Update-

I bought a scanner and erased the code.
The same code comes up within 15 miles of driving. The new oxygen sensor only changed where the call idles at, which is now correct. P0037 comes up again. Scanner says oxygen sensor OK and oxygen sensor heater OK. The codes was set at 20mph. This is also where the car surges. The RPMs with Ranges from 800 to 1200 when off the gas at about 15 to 25 mph. The RPMs will smooth out while coming to a stop but will idle a little rough. Otherwise It runs great on acceleration and anything over 35mph.

Why does this cade keep coming up?

Thanks

You likely need to install a new OEM oxygen sensor, if your new sensor is an aftermarket part. Your ECM keeps having a problem with your current one. ECMs are extremely sensitive to changes in oxygen sensors, where differences are measured in millivolts. I know it can be very frustrating--many of us have been there.

Thanks TXGM.

I did replace it with an OEM part. A $225.00 OEM part.

Try disconnecting the pigtail connector and carefully cleaning contacts, using jeweler files. Other than that, I don't know what else to suggest.

When you replaced the sensor, did you eliminate the previous "repair" that the other guys did to the wiring?

Yes I did. The wiring problem with the solder was on the sensor side of the plug. Another reason I replaced the sensor. The one replaced was a universal one so I wanted to make sure the wiring was hooked up correctly