O2 sensor location

It looks as though there are 3 total, location depends on what series 1.7L engine you have. Per the manual the 2nd and 3rd sensors should be replaced as a set

Heres a guide to read about replacing the oxygen sensors

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

See the diagrams below for locations for all 1.7L engines

It is a 2004 Honda EX. From your Pics i take it that it has two O2 sensors?

No, according to the manual there are 3

where is the oxygen senser located on the car?

Hi jd0977,

They are mounted on the exhaust maniflod, before and after the catalytic converter.

My catalytic converter keeps throwing an engine code p0132, 02 sensor 1 bank 1 high voltage, I have replaced the 02 sensor and the code keeps coming back. And quite often while driving I feel the car shutter and as I try to accelerate the rpm's start dropping and the engine starts losing power until I press the gas pedal all the way to the floor and the rpm's will jerk back up to where it is supposed to be and I have had it sputter out and die multiple times and stop light. When that happens I have to put the car in neutral and rev the engine to keep it from dying.

It could be a plugged catalytic converter or bad wiring between the O2 sensor and the computer. I have included screenshots of the diagnostic steps we have for the P0132 error code.

Engine Mechanical problem
2000 Honda Civic 4 cyl Automatic 6,700 miles
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Check engine light is on. AutoZone read codes PO136 & PO137. Both codes are for oxygen sensor 2 in bank 1. PO136 says a malfunction exists in electrical circuit for the sensor. PO137 says input voltage from sensor is too low for current operating conditions. AutoZone says oxygen sensor 1 is closest to the cylinder head before the catalytic converter, while oxygen sensors 2 & 3 are located further downstream and are typically mounted in or after the catalytic converter. It also says bank 1 identifies the location of cylinder while bank 2 identifies the cylinders on the opposite bank.

Because car is driven so seldom, I'm not concerned about poor gas mileage. Car is running fine so fuel mixture must not be lean. Dealer quoted $220 to replace sensor and said engine isn't being damaged as long as fuel mixture isn't lean. I don't want to spend money to replace sensor. Will there be any problems?

[quote:2dcd80b99f="jigger"]Engine Mechanical problem
2000 Honda Civic 4 cyl Automatic 6,700 miles
----------------------------------------------------------------
Check engine light is on. AutoZone read codes PO136 & PO137. Both codes are for oxygen sensor 2 in bank 1. PO136 says a malfunction exists in electrical circuit for the sensor. PO137 says input voltage from sensor is too low for current operating conditions. AutoZone says oxygen sensor 1 is closest to the cylinder head before the catalytic converter, while oxygen sensors 2 & 3 are located further downstream and are typically mounted in or after the catalytic converter. It also says bank 1 identifies the location of cylinder while bank 2 identifies the cylinders on the opposite bank.

Because car is driven so seldom, I'm not concerned about poor gas mileage. Car is running fine so fuel mixture must not be lean. Dealer quoted $220 to replace sensor and said engine isn't being damaged as long as fuel mixture isn't lean. I don't want to spend money to replace sensor. Will there be any problems?[/quote:2dcd80b99f]

Yes, maybe not in the very near future as long as vehicle isn't driven much, but will eventually cause failure of the Catalytic Converter and can cause engine damage. The sensor being bad will cause rich and lean run times.

You could probably replace the sensors yourself and save at least half if not more. They are not that difficult to change.

I have a 96 honda civic dx(D16y7) 5 speed manual transmission. I recently installed a header in place of the manifold. After install, the car smokes after about 15 sec of run time. I noticed the old manifold had a cat connected to the manifold. This is where the sensor was located. Now the sensor is at the back of the header with the first cat removed. What could be the problems?

Here is an honest answer. You have messed with the system, the O2 is expecting the output to be something after a cat has done its job but now the O2 is getting a richer reading. You will probably experience other issues as well.

I replaced the front oxygen sensor. The rear sensor wires looks like they head into the car on the driver side. Where do I locate the plug from the old sensor?

For the rear sensor, there is a little grommet you must remove, then gently tug on the wiring harness and you'll see the connector. Simply un-clip it and remove.

You may have to remove an exhaust heat-shield to access it.

Hello,

I have a 2004 honda civic ex 1.7L 4 cyc and I want to change the oxygen sensors and I understand that there are 3 oxygen sensors I know where the upstream and downstream are where is the 3rd one located help please?

Hi,

The number of sensors is based on which 1.7L you have. Some have two and others have three. Also, the engine type will determine sensor locations.

Take a look at the pic below. See if it helps. Also, here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

Let me know.

Joe

Hi Joe,

I've located the ones from the bottom of the car but I can't find the 3rd one. I have a 2004 Honda Civic ex 1.7L 4 cylinder sedan I think it's a v tech.

Hi Joe,

I bought the car from a neighbor and it came without the manual. how would I know what engine my car has? where can I buy the manual?

Hi,

The 8th digit on the vehicle identification number (VIN) is the engine code. Can you let me know what it is?

Since you found the ones under the vehicle, that leaves one more that is likely on the exhaust manifold. If you look at the attached pic, I highlighted where to look. Note: It will be in the front of the engine and on top of the manifold. It isn't indicated in the top pic, but I highlighted where it should be.

Let me know.

Joe

See pic below.