Hi.

I got following errors P0030/P0130/P0134 on mazda3 2009 petrol DOHC16
The O2 sensor on manifold was replaced (3 times) but the error codes are still there.

Any ideas?

P0030 - H02S Heater Control Circuit Bank1 Sensor1
P0130- 02 Sensor Circuit Bank1 Sensor1
P0134 - 02 Sensor Circuit No Activity Detected Bank1 Sensor1

 

DIY first rule is DON"T start replacing parts you have not yet verified them to be fault! A DTC does not mean the part associated to a DTC is a problem,it only means that that area is not reporting properly to the ECU and the monitors are indicating the engine is expelling excess emissions. .
You must do the work....that is look and find a problem solving tree and follow it having to do with the DTC'S your are getting in the trouble code file hopefully accessed directly at the OBDII diagnostic connector and not a remote blue tooth device.

If it were as simple as looking at a DTC and replacing a part there would be no more need for trained Auto Technicians


If it had been a H02 issue then replacing it or at least assuming a possible defective first one the second replacement would have corrected the issue causing the DTC. But 3 H02 replacements... lol stop! lol.

 

Yeah I agree.
Its my friend. He understood cars 30 years ago when no much electronics was there but he admitted he is lost now.
He is not internet person so I decided to help him. His next move is to replace H02 with original part from Mazda which cost something like £270.

IMHO I dont think it will solve anything.

Yes I use Autolink AL319 wire

My next move is to test connectors and measure the O2 sensor as well as wires.
Found on youtube -
I found as well fuses diagram and it looks like 32 &33 are the 02 10A fuses to check.
Youtube - Mazda3 fuses

Will report back if I find/dont find anything.

 

Good follow up and I appreciate the positive response.

 

Are you aware there are two sensors in the exhaust?

Bank 1 Sensor 1 is the Air Fuel Sensor (A/F) Usually mounted in the exhaust Manifold.
Bank 1 Sensor 2 is the Oxygen sensor (O2) Usually mounted in or behind the Catalytic convertor.

 

Yes I have seen some videos on Youtube where they replace both of them.

As I mentioned I am getting below errors:
Those errors suggesst Air Fuel Sensor reading to be incorrect. I will measure both today just to be safe.
Thanks

 

The AF sensor is there to tell the ECU the engine is running rich or lean.
If the the engine has a unmetered air leak, leaning the engine out the AF sensor will report this. A lean or rich code doesn't condemn the AF or O2 sensor.

Also I've had to replace faulty PCM's due to heater circuit issues, very uncommon, but possible. Complete & methodical diagnosis is required.

 

Ok - so I measure the O2 Sensor and connector. Both of them looks good.
The O2 sensor gives reading of 3.8 Ohm and connector 12.4V but only on one pin.
So there are 4 pins and on the above youtube video the guy gets reading on all 4 pins - I am getting reading on only one pin - not sure if that has something to do with the engine light.

Any ideas?

Another thing is that I have not found fuses for the O2 sensors.
On the second post I added Mazda3 fuses diagram but this mazda3 has different fuses layout and there is not fuses for O2

Does anybody know if the male connector should click or something when I connect the sensor to it? Right now I can unconnect them without pressing the plastic on top.
It might be somthing with the connector. If so where can I buy such connector? Cannot find on internet or shoould I just get rid of those connectors and connect it directly (a little harsh approach )

 

Can anybody confirm I should get reading on all 4 pins on male O2 (A/F) connector?

I assume its directly connected to PCM?
So if there should be reading and I dont get any that would point to PCM issue probably.

 

Nobody who could verify the readings on theirs car?