MichaelHumphreys

2003 Fiesta O2 Sensor Issue

Recommended Posts

Hi all,

I have recently purchased my first car, which happens to be a 53 plate 1.4 Fiesta Zetec and after owning it for around a month the engine management light came on. So I plugged in a basic diognostic checker and found that it was the Heater Control Circuit Bank 1 Sensor 1 that was causing the issue. So I checked the wiring, and the sensor exterior but could not remove the sensor from the engine bay to check it. I erased the engine light and it came straight back on when the engine was started up. SO i took it to the garage and asked them to check the light, replace the sensor and then erase the light. A medium sized garage bill later the sensor was replaced. However the light continues to stay on after replacement and after removing the light.

Does anyone know what else I can check to stop the light coming back? I know jumping to changing the sensor is wrong but I really thought that it was the issue seen as the car was coming up to 70k miles.

Thanks

Share this post


Link to post
Share on other sites

did they change the correct sensor, there are 2, upstream and downstream of the cat. bank 1 sensor 1 is the upstream one.

check fuse 13 20amp is ok

Share this post


Link to post
Share on other sites

Hi, thanks for a quick response. They definitely replaces sensor 1 which is located just behind the air filter in the engine bay. I checked the fuse just now and its okay which is a pain as I still haven't found a fix and I'm worried about by cat :/. Thank you though

Share this post


Link to post
Share on other sites

Hi,

I have a 2015 MK7 Ford Fiesta Red Edition 1.0 ecoboost 140bhp. The car has just hit the 50k mark and the engine managment light has come on. I tested it with an OBD2 reader and it turns out it was the Oxygen (lamda) Sensor Bank 1 Sensor 1 (pre cat). I managed to get my hands on one and had it replaced and cleared the code using OB2 reader. i drove about two miles and turned the car off and back on and to my suprise the engine managment light came back on, I then reset my ECU by dissconnecting the battery from the car and left it for 10 mins before reconnecting it however the light is still on.

I have read something about drive cycles and how the car needs to go through a certian number of drive cycles before the monitoring system resets and could even be up to 100 Miles. Does anyone know anything about this or anything els i could try or if this drive cycle thing is even a thing?

Share this post


Link to post
Share on other sites

Hi,

I have a 2015 MK7 Ford Fiesta Red Edition 1.0 ecoboost 140bhp. The car has just hit the 50k mark and the engine managment light has come on. I tested it with an OBD2 reader and it turns out it was the Oxygen (lamda) Sensor Bank 1 Sensor 1 (pre cat). I managed to get my hands on one and had it replaced and cleared the code using OB2 reader. i drove about two miles and turned the car off and back on and to my suprise the engine managment light came back on, I then reset my ECU by dissconnecting the battery from the car and left it for 10 mins before reconnecting it however the light is still on.

I have read something about drive cycles and how the car needs to go through a certian number of drive cycles before the monitoring system resets and could even be up to 100 Miles. Does anyone know anything about this or anything els i could try or if this drive cycle thing is even a thing?

Share this post


Link to post
Share on other sites

What was the fault code you got? A fault code relating to an oxygen sensor doesn’t necessarily mean it is faulty in any way. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.