Question about 2003 Ford Focus

1 Answer

Where the monoxid carbon sensor are locater - 2003 Ford Focus

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Ford Master
  • 17,970 Answers

The oxygen sensors are located in the exhaust pipe, before and after the catalytic converter.

where the monoxid carbon sensor are locater - 14fd61b.jpg

Fig. Showing the typical locations of the heated oxygen sensors

Hope helps (remember comment and rated this).

Posted on Jul 29, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

What will happen if i disable the sensors responsible for the carbon monoxide on the pajero v6 1997 model

The light will come or stay on. And your fuel mileage will take a nose dive...

Apr 14, 2016 | 1997 Mitsubishi Pajero

1 Answer

Catlis system below thresh hold bank 1

Catalyst System efficiency below threshold means that the O2 sensor behind the catalytic converter is reading more hydro carbons than what it views as normal. Either, your catalytic converter is bad and not changing the carbon monoxide into less volatile gases or you have something upstream causing the issue; it is running too rich, etc.

Dec 26, 2014 | 2000 Plymouth Voyager

1 Answer

What are the fuctions of oxygen sensors on the 1997 pajer V6 3500

Upstream sensors ( before the catalytic converter ) are responsible for initial fuel air mix, and Down stream sensors are responsible for Carbon Monoxide levels as well as other emissions.

May 07, 2014 | 1997 Mitsubishi Pajero

1 Answer

Losing compression in 3rd cylinder, will it effect 02 sensors?

It monitors your car's exhaust emissions, especially hydrocarbons and carbon monoxide.--------------------------------------------------------------------------
vas 5054a v19

Nov 30, 2012 | Ford Explorer Cars & Trucks

1 Answer

Carbon monoxide

This is a toxic gas producted by the burning of gasoline, if the level in the exhaust is really high you may have engine problems.

Feb 14, 2012 | 1998 GMC Safari

1 Answer


i woulsd try and change the o2 sensor located Under hood, passenger side, lower engine area, mounted in exhaust manifold ,and you have a catalytic convertor has it ever been changed i had an s-10 that always barely passed inspection even when brand new good luck

Jan 31, 2010 | 1993 Chevrolet S-10

1 Answer


2002 PCED OBDII-Villager SECTION 1: Description and Operation Catalyst and Exhaust System Overview The catalytic converter and exhaust system work together to control the release of harmful engine exhaust emissions into the atmosphere. The engine exhaust gas consists mainly of nitrogen, carbon dioxide and water vapor. However, it also contains carbon monoxide, oxides of nitrogen, hydrogen, and various unburned hydrocarbons. Carbon monoxide, oxides of nitrogen, and hydrocarbons are major air pollutants, and emission into the atmosphere must be controlled.
The exhaust system consists of an exhaust manifold combined with a pre-catalytic converter, upstream heated oxygen sensor (HO2S11), (located just in front of the pre-catalytic converter), three way catalytic converter (TWC), downstream heated oxygen sensor (HO2S12) (located in front of the TWC), a muffler and an exhaust tailpipe.
Heated Oxygen Sensors The Villager is equipped with both upstream and downstream heated oxygen sensors (HO2S) (Figure 1). The upstream heated oxygen sensor (HO2S11) is used to control engine fuel flow. The sensor detects the concentration of oxygen in the exhaust gas and sends a signal to the powertrain control module (PCM). In a rich condition, the HO2S will output a voltage of 0.6 volts or greater, and in a lean condition a voltage of 0.4 volts or less will be output.
The downstream heated oxygen sensor (HO2S12) is used primarily for monitoring the efficiency of the catalytic converter system. The HO2S12 works in a similar way to the HO2S11 but only indicates to the PCM that the catalyst is functioning properly. In the event that the HO2S11 fails, fuel control will be switched over to the HO2S12 and the malfunction indicator lamp (MIL) will be illuminated. This allows the vehicle to operate with fewer emissions, even with a sensor failure.
Figure 1: Typical Heated Oxygen Sensor (HO2S)

Feb 21, 2009 | 2002 Mercury Villager

1 Answer

1986 camaro emissions problem- 6 cylinder stick

high hydrocarbons indicates head gasket(1 or both) leaking , carbon monoxide is a worn out catylitic convertor which both could lead to the oxy sensor getting a false reading

Oct 28, 2008 | 1986 Chevrolet Camaro

Not finding what you are looking for?
2003 Ford Focus Logo

94 people viewed this question

Ask a Question

Usually answered in minutes!

Top Ford Experts


Level 3 Expert

81342 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

gerry bissi

Level 3 Expert

4376 Answers

Are you a Ford Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides